Flood modelling bolstered by data overhaul

Posted 2 December 2016

Brisbane floodFlood modelling should be more accurate and accessible following the first major upgrade of the Australian Rainfall and Runoff (ARR) Guidelines in three decades.

The update is the result of four years' collaboration between Geoscience Australia and Engineers Australia, with the Bureau of Meteorology providing nearly 30 extra years of rainfall data.

“We’ve undertaken a complete revision of the Guidelines to ensure they are a comprehensive and truly national product,” said Geoscience Australia Chief Executive Officer Dr Chris Pigram.

“For the first time, the guidelines are completely based on Australian data. They include data from an extra 30 years of observations from across the continent, including at least 100,000 storm events.”

The upgrade was prompted by a review into a series of floods in the summer of 2010-11, including the Brisbane floods.

Pigram said not only had the data been updated and improved, but the guidelines were now publicly and freely available online too.

BoM Chief Executive Officer and Director Dr Andrew Johnson added that the guidelines now included the bureau's new Intensity–Frequency–Duration (IFD) design rainfall estimates.

“The new IFDs more accurately estimate rainfall intensity, frequency and duration in specific locations, which helps Australia to reduce the potential damaging impact of future floods,” Johnson said.

The estimates include observations from over 10,000 rainfall gauging stations, including 2300 extra rainfall stations and nearly three decades of additional rainfall data.

“We’ve also used statistical analysis techniques that weren’t available 30 years ago,” Johnson said.

Engineers Australia Chief Executive Officer Stephen Durkin said the comprehensive revision would be invaluable today and into the future.

“More accurate, consistent data sets and guidance means more accurate and consistent flood studies and mapping. This is not only good news for engineers and town planners, but for also for Australians living in areas with a flood risk,” Durkin said.

Engineers and town planners have been using the ARR Guidelines for almost 60 years to develop accurate and consistent flood studies and mapping across Australia.

These are then used to design dams, stormwater drainage, improve floodplain management and assist land managers with soil conservation strategies.