CSIRO dam break modelling to help flood planning

The research has been helping China’s disaster management authorities better understand the full impact of the catastrophic flooding that would occur if one of China’s, and the world’s, biggest dams collapsed.

The work could also be applied in Australia to help plan for extreme weather events.

Working with China’s Satellite Surveying & Mapping Application Centre (SASMAC), CSIRO scientists have modelled the effects of a catastrophic failure of the massive Geheyan Dam in China’s Hubei province. They have simulated the impact of flooding on the surrounding region and its infrastructure if the dam suddenly released its 3.12 billion cubic metres of water.

The Geheyan Dam holds more than five times the volume of water in Sydney Harbour. Dam failure is of particular concern in China because many of the country’s 70,000 dams are in regions prone to earthquakes.

“We modelled six different dam failure scenarios,” said CSIRO computational scientist, Dr Mahesh Prakash. “Our simulations show where the water would go, how fast it would reach important infrastructure such as power stations and the extent of inundation in major townships downstream.”

SASMAC’s Professor Xinming Tang said the project is immensely important for disaster management planning.

“Seeing the possible consequences of dam failure enables us to develop appropriate emergency procedures as well as plan new infrastructure safely,” Professor Tang said.

CSIRO’s innovative approach combines data that changes over time – the water flow – with static landscape data from a Geographic Information System to show how infrastructure will be affected.

“The modelling technique we developed for this work is really powerful,” Dr Prakash said. “It gives us very realistic water simulations including difficult-to-model behaviours such as wave motion, fragmentation and splashing.” 

The team at CSIRO used the same technique and software to model other catastrophic geophysical flow events like tsunamis, floods, storm surges as well as landslides and volcanoes. The technique was tested by modelling the 1928 St Francis dam break in California which produced a very accurate simulation of what happened in real life.

The project is funded under the Australia-China Environment Development Partnership (ACEDP) by the Australian Agency for International Development (AusAID).