Bruce Laity on his farm 30kms from Kerang in northern Victoria. Photo: Simon O Dwyer
Victorians may face even worse fire conditions next summer, with a new study estimating there is a 76 per cent chance of an El Nino weather pattern in the Pacific.
An El Nino typically sees rainfall shift east away from Australia and is linked to dryness and active fire seasons in the country's south-east.
Melbourne University fire ecologist Kevin Tolhurst said a likely El Nino, as suggested by a German study published in US journal the Proceedings of the National Academy of Sciences, would increase the bushfire risk.
Last six months: rain in Australia falls mainly in the west. Photo: BoM
''We're heading back into a dry period again,'' Professor Tolhurst said. ''In El Nino years, you have much larger and more destructive fires because there's much more of the landscape available to burn.''
He said fire authorities should devote more resources to suppressing fires, not just in El Nino years. That effort relies less on “our big helicopters and the massive numbers of fire trucks – which are all really important in the emergency situation”, he said. Rather, “this is the hard slog, days after the main fire run has finished, before the next series of bad weather.”
El Nino signs
The Bureau of Meteorology said neutral conditions for the El Nino-Southern Oscillation were likely to persist until the end of autumn at least, but warming of the Pacific was likely in coming months. It said some models indicated temperatures in the central Pacific could approach El Nino levels by early winter.
Ross Bradstock, a bushfire expert at the University of Wollongong, said the severity of Victoria's fire season would be determined by interplay between an El Nino and conditions in the Indian Ocean.
A cooler-than-usual eastern Indian Ocean, known as a positive Indian Ocean Dipole, is also associated with a drop in rainfall in central and southern Australia.
''If you have a positive Indian Ocean Dipole event, possibly in interaction with an El Nino event, it may favour the incidence historically of major fires in Victoria,'' Professor Bradstock said.
NSW, which had less than a third of its normal rain in January, would also likely have more bushfires in an El Nino year. "El Nino effects do increase the severity of fire weather, that’s been shown historically for NSW, Professor Bradstock said.
One sign Victoria’s drying out is that Melbourne’s water storages fell 0.8 per cent last week, the biggest weekly drop in 11 years, Melbourne Water said.
2013, Austrralia's hottest year on record, was also a dry one for much of the country. Rainfall in the key Murray-Darling Basin was 24 per cent below average, while Victoria had its 14th below-average year of rainfall in the past 17 years, the bureau said last month.
Summer crops down
Meanwhile, the Australian Bureau of Agricultural and Reource Economics and Sciences said, heatwaves and spreading drought were likely to cut the output of summer crops for 2013-14 by 25 per cent, pushing it to its lowest in four years.
Peter Collins, manager of the bureau's agricultural commodities unit, said it was too early to say if El Nino conditions would take hold, but many farmers were already struggling with low soil moisture.
''A continuation of this dry weather would not be good news for next season's winter crop,'' Mr Collins said.
While the winter crop was a bumper one, land planted for summer crops fell 15 per cent on a year earlier. Output is expected to drop by 25 per cent, the bureau said.