What’s causing Australia ‘super floods’?
By Megan Neil
February 11, 2011 As Dudley Maslen watched in horror TV footage of the deadly ‘inland tsunami’ raging across southeast Queensland, it reminded him of September 11. ”To me, it was a bit like watching that 9/11,” he recalls. ”You’re watching it and it’s real but it’s just unbelievable. It’s just staggering, the absolute tragedy of it.” Mr Maslen was far from Toowoomba – about 3800km away, in the small West Australian town of Carnarvon – where he is shire president. At the time, Carnarvon was still reeling from its own devastating floods.From WA’s Gascoyne region to most of Queensland, from central Australia to Tasmania, the summer in the ”Sunburnt Country” has been a story of rainfall of almost biblical intensity. Along the Gascoyne River in northwestern WA, half a dozen homesteads that had stood for 120 years on pastoral stations couldn’t withstand the December floods. Some parts of the region had their average annual rainfall – 200 to 300mm – in the space of one or two days, swamping irrigation equipment and vegetable crops. … A month after a deadly wall of water cascaded through Toowoomba and the Lockyer Valley in Queensland, the nation’s floods crisis isn’t over yet. Last weekend, Victoria copped its fourth major flood since September, courtesy of moisture from Tropical Cyclone Yasi and her predecessor Anthony. As well as the flood-weary northwest of the state, Melbourne’s southeastern suburbs and parts of Gippsland were swamped. Thanks to Yasi’s remnants, homesteads and communities in South Australia’s north were cut off and even Alice Springs copped a drenching. Yasi compounded the problems in Queensland, where residents have lived through five weeks of flooding and then cyclones. ”The worst floods in our history across three-quarters of the state followed by the worst cyclone, over a huge area, in almost a century,” Queensland Premier Anna Bligh said. … Victoria had already experienced its wettest January on record by the halfway mark of the month. It was the wettest December on record for Queensland (209.5mm) and eastern Australia (167.2mm), coming after an extremely wet spring. Even the outback NSW mining town of Broken Hill received half its annual rainfall – of about 240mm – over a four-day period in January although it was the vast area of land around the city that was hit by flooding. … La Nina is the dominant driver of the high rainfall but climate scientists aren’t excluding any role for climate change. ”The strong La Niña is the primary cause of this very high rainfall season we’ve had,” said Professor Matthew England, co-director of the Climate Change Research Centre at the University of NSW. ”However, I would argue that the ocean warming trend north of Australia, driven by climate change, has also played a role, as this region feeds moisture into the atmosphere, and determines how strong the monsoon rains are.” Experts say more rain and floods will come and thought needs to be given to how we manage living on floodplains. The state, as Ms Bligh has said, faces a reconstruction task of post-war proportions. …
