Flood risk predictions could be carried out up to 1000 times faster using new techniques, according to researchers.

A University of Adelaide study, published in this month’s Journal of Hydrology, says climate change will turn flood risk assessments into “a major challenge”.

“Approaches typically used by industry for flood risk assessment have been based on information about historical flood events,” lead author Mark Thyer says. “But climate change will eventually make that method obsolete, because with a change in climate those historical events start to become more irrelevant as predictors of future flood activity.”

The main contender for predicting flood events under climate change, called continuous simulation, can be “incredibly slow”, because it uses long-term rainfall sequences spanning hundreds of years.

“This can take anywhere from weeks to months to generate an accurate prediction for a single catchment,” Professor Thyer says. “The new method tested by the [university’s] research team is aimed at providing a highly accurate assessment at a much faster rate.”

The method, known as hybrid causative events, relies on an algorithm that knocks out all unnecessary information used in the slower, continuous simulation approach, such as long periods without rainfall.

“So far our method has been tested in a virtual laboratory on eight different sites in Australia,” Professor Thyer says. “We’ve found it to be highly accurate at each location, and increasing the speed of the flood prediction by between 100-1000 times compared with continuous simulation.”

It is expected to take about five years for the new method to be available to industry.