Toa Payo: PonteSud – News Desk
In the driest region of the world’s driest inhabited continent, a vast inland lake that is typically dry is slowly filling with water, marking a rare event that is set to transform the desert region and attract birdlife from as far away as China.
The outback lake, Kati Thanda-Lake Eyre, which is about 12 times the size of Singapore, is in central Australia, about 750km north of the city of Adelaide. Typically, the lake, which has filled up to capacity only three times in the past 160 years, is a flat, dry salt pan that receives just 140 millimetres of rain a year.
But waters from massive floods in the state of Queensland hundreds of kilometres to the north-east, in March and April, have been slowly making their way along a sprawling network of waterways towards Lake Eyre, which marks the lowest point on the continent.
The lake has started to fill and could even surpass the levels of the last such event in 1974, when it reached a depth of six metres, the largest filling of the lake, which would make it the most full that it has been in recorded history.
The filling of the lake, which covers more than 9,000 sq km, is set to turn the area into a hub of wildlife, including various species of fish and millions of birds such as pelicans, ducks and seagulls that can arrive from across South-east Asia, China and Papua New Guinea.
Other wildlife include invertebrates such as brine shrimp, whose fertilised eggs can sit beneath the salt pan for decades until the arrival of water, which enables them to hatch. The water in the lake triggers a food web that starts with the generation of “algae and plankton, and then things take off”, an expert on dryland rivers, Professor Fran Sheldon, head of the School of Environment and Science at Griffith University.
She said the filling of the lake could help to address declines in bird populations that have been occurring in recent decades due to loss of habitat, mainly caused by urban development and farming. Scientists are still trying to understand how birds know that Lake Eyre has water. But the phenomenon is not a sure guarantee of survival for the birds.
Much of the water arriving at the lake has come from northern and western Queensland, which experienced devastating floods that led to the loss of an estimated 100,000 heads of cattle, sheep and goats and caused damage worth tens of millions of dollars. But the waters, which have been travelling hundreds of kilometres at roughly walking pace, are proving a boon for the lake region.
Water to evaporate in one to two years
The water is likely to stay in the lake and gradually evaporate over the next one to two years, an expert on resource management and climate change, Professor Steve Turton, from Central Queensland University, told The Straits Times.
The water will evaporate at a rate of about 1.5m to 2m in depth each year, and there will also be loss of water due to seepage, he said. Prof Turton said the current filling of Lake Eyre is unusual because it involves rains that did not fall during a La Nina weather event, which would usually bring more rain, and did not fall during summer.
He said climate change has increased air temperatures, boosting the amount of water vapour in the air and causing massive rain events such as the flooding in Queensland. He said global warming will add to evaporation and so will not necessarily make the filling of Lake Eyre more frequent, but could lead to it filling to ever new record levels.
Though the lake partially filled in 2010 and 2019, it has only ever reached capacity in 1950, 1974 and 1984 since records began in the 1860s. But it is now expected to fill by October, when its levels are set to peak.
Mr Wright said the spectacle, and the wildlife, have already begun to attract tourists to the remote area, where summer temperatures can exceed 50 deg C. Despite the remote location, there are some outback hotels nearby and several operators offering scenic flights.
