Extreme rainfall scenarios affect infrastructure planning

The climate of 2040 is likely to bring more intense and more frequent extreme rainfall events to coastal eastern Australia, according to ...

The climate of 2040 is likely to bring more intense and more frequent extreme rainfall events to coastal eastern Australia, according to Dr. Debbie Abbs, a climate scientist at the Commonwealth Scientific Investigation and Research Organisation’s (CSIRO) Atmospheric Research in Melbourne, Australia.

Climatologists have suggested for some time that climate change would lead to more intense rainfall globally; however results from a computer model focusing on regional Australia indicate small areas receive much more extreme rainfall.

Dr. Abbs explained: “Global climate models simulate rainfall over areas as wide as 200 kilometres. Extreme rainfall over small areas is much more than that found over large areas where results are averaged out. This means there is a need to provide extreme rainfall scenarios at regional scales so projected climate change can be factored into major infrastructure projects that are being designed to last for decades to come.”

“The most extreme rainfall events we currently experience become more frequent in 2040, with the 1-in-40-year event of today corresponding with a 1-in-15 year event in future,” she continued. “The areas of greatest increase in intensity occur over mountainous terrain, inland from Coffs Harbour, Coolangatta and north of Brisbane.”

Each year extreme rainfall events cause significant damage from flooding in the highly urbanised regions along Australia’s eastern coastline where populations are increasing. A 26% increase in flooding leads to a 60% increase in damage costs. “With projected increases in the intensity and frequency of extreme precipitation events, the community’s exposure to extreme rainfall events is growing rapidly,” said Dr. Abbs.

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