Australia could soon face megadroughts that last for decades, a research warns.

In the study, researchers from the Australian National University (ANU) used multiple climate models to simulate droughts that occurred in Australia between the years 850 and 2000 to determine how they might change in the future.

They found that droughts in south-western and eastern Australia in the 20th century were longer on average than those in pre-industrial times and warned that Australia could soon face megadroughts that last up to 20 years with effects that are exacerbated by climate change.

"One of the confronting findings of our work is that it is possible for droughts in Australia to be much longer than any of the droughts that we've experienced in recent times. Droughts that continue for 20 years or more are something that we should expect to happen," Georgy Falster, co-lead author of the research from the ANU Research School of Earth Sciences, said in a media release on Tuesday.

"Megadroughts are part of the natural variations in Australia's climate. But worryingly we are now also adding human-caused climate change into the mix, and that is probably increasing the chances of the next megadrought here."

According to the study, a megadrought is an exceptionally severe, long-lasting and widespread drought.

The researchers focused their efforts on the Murray-Darling basin, Australia's largest agricultural area including parts of South Australia (SA), New South Wales, Victoria, Queensland and the Australian Capital Territory (ACT).

They found that human-caused climate change is already contributing to longer droughts in the basin as well as southwestern Australia and that those regions could expect future declines in rainfall due to climate change, increasing the risk of droughts.

In order to reduce the impact of future droughts, the researchers said Australians should be prepared with water storage and management plans and community support networks.