There’s “an implicit assumption that no matter how big a disturbance is, the water will always come back — it’s just a matter of how long it takes,” says Tim Peterson, a hydrologist at Monash University in Melbourne, Australia. “I’ve never been satisfied with that.”
The years-long drought in southeastern Australia, which began sometime between 1997 and 2001 and lasted until 2010, offered a natural experiment to test this assumption, he says. “It wasn’t the most severe drought” the region has ever experienced, but it was the longest period of low rainfall in the region since about 1900.
Peterson and colleagues analyzed annual and seasonal streamflow rates in 161 river basins in the region from before, during and after the drought. By 2017, they found, 37 percent of those river basins still weren’t seeing the amount of water flow that they had predrought. Furthermore, of those low-flow rivers, the vast majority — 80 percent — also show no signs that they might recover in the future, the team found.
The years-long drought in southeastern Australia, which began sometime between 1997 and 2001 and lasted until 2010, offered a natural experiment to test this assumption, he says. “It wasn’t the most severe drought” the region has ever experienced, but it was the longest period of low rainfall in the region since about 1900.
Peterson and colleagues analyzed annual and seasonal streamflow rates in 161 river basins in the region from before, during and after the drought. By 2017, they found, 37 percent of those river basins still weren’t seeing the amount of water flow that they had predrought. Furthermore, of those low-flow rivers, the vast majority — 80 percent — also show no signs that they might recover in the future, the team found.
