Australia — Global warming and Eucalypt regrowth in the alpine region coulddrastically reduce mountain water supplies crucial to Australia’s biggest riversystem, new research suggests.
Studies from the Australian Greenhouse Office and the CSIRO already predictsnow will no longer fall on the Snowy Mountains and bushfires will become morefrequent and severe by 2050.
The reduced snowmelt run-off will drastically reduce the amount of waterflowing into Snowy-Hydro storages and the Murrumbidgee River, cutting flows inthe Murray-Darling Basin and affecting water supplies as far as Adelaide.
But scientists from the High Country Fuels and Ecosystem Functions (HCFEF)team say an equal, but less understood, threat to water supplies will beeucalypt regrowth after bushfires.
University of NSW Professor Mark Adams, a member of the HCFEF, said severebushfires could potentially wipe out up to half a million hectares of bushlandin the alpine region.
“Bushfires create large scale forest regeneration that uses more waterthan the mature forests they replaced,” Prof Adams said.
Regrowth from fire posed a major threat to the security of future watersupply in the alpine region which feeds cities, agriculture and much ofAustralia’s economy, he said.
“Research shows that the 2003 fires that ravished eastern Australia werelikely to reduce water flows by more than 20 per cent for the next 20 to 30years,” Prof Adams said.
The research indicates a large bushfire in the alpine region could reducewater supplies by up to 20 per cent, 30 years after the event.
A 20 per cent reduction to the region’s water supplies would be devastating,the professor warned. “If the prognosis is right with reduced rainfall and snow, a bushfire wouldhave a long-lasting effect,” Prof Adams said.
“We will never be able to stop bushfires, but we must try to mitigatethe effects.”
The $1.7 million, federal government-funded research project, prompted by the2003 bushfires in the alpine region, will monitor the complex relationshipbetween water, soil, trees and fire.
Prof Adams said HCFEF was the first research project in Australia to measurethe threat of bushfires to water supplies in the region.
The team, including scientists from three Australian universities, theBushfire Cooperative Research Centre and the CSIRO, hopes to develop managementimplications for present and future fire regimes to reduce the impact on futurewater supplies.