Scientists see through clouds for faster flood info

Image: Wes Warren, Unsplash

New techniques to see through clouds and map flooding have been developed by researchers in Australia.

The University of Queensland says that using satellites and radar imaging sensors could provide faster, more detailed information to keep communities safe. Professor Noam Levin from the university’s School of Earth and Environmental Sciences says the project combined images from optical satellites with information from imaging radar satellites.

He explains, “Monitoring floods in towns and cities is challenging, with flood waters often rising and then receding in a few days. While large satellites in the past provided images every seven to 14 days, now groups of small satellites can collect several images a day over the same location.

"Radar imaging sensors can provide images at night or on days with thick cloud cover – a huge advantage in stormy conditions. They use a flash, like on a camera, and the light is sent at wavelengths between 1mm and 1.0m, which can pass through clouds and smoke.”

Image: Kelly Sikkema, Unsplash

“With faster update times and more accurate and timely data, agencies monitoring the floods can assess changes and alert people in at-risk areas."

Professor Stuart Phinn, University of Queensland

A series of unprecedented floods occurred in eastern Australia, from February to April 2022, when a national emergency was declared. In the city of Brisbane, where 177 suburbs were impacted, researchers combined satellite daytime pictures showing the extent of the flood with imaging radar and optical nighttime data of the lights associated with human activity.

Levin said: “We could see which areas became dark as the flood waters encroached. We matched this with data from river gauges operated by the Bureau of Meteorology, and with changes in electricity loads reported by Energex, the power supplier.”

Professor Stuart Phinn, also of the School of Earth and Environmental Sciences, said the technique could play a vital role in protecting Australians during future flooding events.

“In combination with existing flood monitoring and modelling technologies, satellites could change the way we monitor major flood events, understand how they occur, and direct emergency and other responses.

“With faster update times – at least twice a day – and more accurate and timely data, agencies monitoring the floods can assess changes and alert people in at-risk areas.

“This technique can also be used post-disaster to assess the extent of damage, direct recovery efforts and for the assessment of insurance claims.”