Clare Kenyon
Floods are now a ubiquitous disaster anywhere in the world – this month alone there have been deaths in floods in the US, Africa, South America, and Europe.
Australia is currently experiencing the consequences of a third La Niña weather pattern in a row and even a remote prospect of a fourth. Creeks are swollen and rivers burst their banks as the floods creep slowly and sometimes with frightening speed.
These events have two things in common – sodden ground that simply cannot absorb any more water, and the need to get better at monitoring and modelling floods so we can better assess and respond to weather changes.
Monitoring and modelling flooding remains a challenge, though, as conditions can change rapidly.
Somewhat ironically, help could come from above the very clouds responsible for the floods.
Researchers at The University of Queensland (UQ) have found a way to better map flooding by combining satellite radar data (e.g., from Capella) with optical images (from satellites such as Planet Inc. and NASA’s VIIRS). Combined with information such as river gauges and changes in electrical energy loads, the technique could provide more frequent updates to river conditions and enable faster response times.
Small groups of these satellites are able to take provide several images a day, a vast improvement on previous satellite imaging turnarounds of weeks. The radar sensors are also capable of working at night and can see through storms, clouds and smoke.
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“Radar imaging sensors can provide images at night or on days with thick cloud cover – a huge advantage in stormy conditions,” Professor Noam Levin from UQ’s School of Earth and Environmental Sciences. “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.”
By combining several different data inputs, the technology could not only help improve our response to flooding in the future, but also assist in responding to affected regions post-event.
“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,” said Levin.
“This technique can also be used post-disaster to assess the extent of damage, direct recovery efforts and for the assessment of insurance claims.”