Bath time’s over but it’s not a disaster

By Lou Morrissey

We know we’re pretty groovy, but you probably don’t think of us when you’re having a bath. Or of the very clever Dr Mahesh Prakash. But perhaps that’s about to change…

Dr Prakash is a fluids modeller, and today he’s speaking at the Coast to Coast Conference in Brisbane to explain why it’s time for computer models of tsunamis and storm surges to get out of the bath. More realistic models are needed for infrastructure planners and emergency managers to better prepare for disasters.

He said his team’s maths-based models are more true-to-life than the standard ‘bathtub’ models and that CSIRO leads the world in this area of fluids modelling.

Hypothetical tsunami off Fremantle (WA) modelled using CSIRO computer models. Rottnest Island is on the left.

“Our work is a big improvement on the simple ‘bathtub’ computer models which show water levels going up evenly like they do when you fill your bath.

“The reality of a storm surge or tsunami is very different – the water is moving, often with a lot of force and it interacts with things that get in its way,” he said.

With coastal storms increasing in frequency and severity and last year’s tsunami in Japan still in recent memory, understanding coastal inundation processes is more important than ever – and computer models can help.

CSIRO’s models can show how fast the water moves, how soon it reaches natural and manmade landscape features, how long it stays at peak levels, the size of the forces it generates on specified buildings, bridges, roads and other structures and whether these structures are recoverable.

Fictional street being flooded by massive wave using CSIRO computer model.

“Basically, our models help us predict quite accurately which coastal areas will be affected and how much damage could occur to specific infrastructure if a disaster happens,” Dr Prakash said.

“Hurricane Katrina, the Japan earthquake and tsunami – these are recent events where some man-made structures failed to protect communities. We can use computer models to test structures before they’re built and find out which parts of a city are vulnerable. That way we can help decision makers make communities more resilient,” he said.

The computer models are the result of more than a decade’s work in computer algorithms and supercomputers.

Find out more here.