Satellites could help tackle flooding crisis, scientists say

A Scottish university has discovered a pioneering method to monitor flooding risks via satellite data.     

Satellite video footage could become an early warning system for flooding, allowing for appropriate on-the-ground planning, researchers from the University of Glasgow have revealed.   

The discovery follows recent severe flooding across Scotland caused by Storm Babet and Storm Ciarán.     

Parts of the East of Scotland experienced 235.9mm of rain throughout October – more than 80 per cent above the monthly average.    

According to the Scottish Fire and Rescue Service, flooding incidents have been on the rise, with over 1,500 more occurrences during 2022/23 than in the 12 months previous.     

Christopher Masafu, author of the paper, said: “Close to 30 per cent of the world’s population is exposed to flood risk and threats to the availability of fresh water.     

“Despite that, many rivers don’t have stream gauges or other measurements in place, which limits how much we can learn about their flows and any potential risks they may pose to local populations during heavy rains.”    

By analysing footage from a Chinese satellite, researchers were able to measure the discharge of a flood along a 12-mile section of the Darling River in Australia.    

They developed techniques to track and analyse the movement of visible surface features between frames in the video footage and later combined flow estimates with detailed elevation maps of the flooded area, providing a flow discharge to be within 15 per cent of real measurements taken by stream gauges.  

Currently, river flows are often measured using stream gauges, which are expensive and difficult to install in remote areas.  

In comparison, satellites can be deployed anywhere “relatively cheaply and easily”, Masafu said.   

Satellite footage also allowed for a more in-depth insight into the phenomenon. By providing a broader visual overview of large areas, video sensors could monitor geographical changes over time and the real-time spread of floods.    

However, Martin Hurst, co-author of the paper, believes there is still work to be done.   

He said: “There are limitations to the work we’ve demonstrated so far – the main one is that the measurement technique can only be used on footage captured during periods without cloud cover.”   

The team has published their paper, titled ‘Satellite Video Remote Sensing for Estimation of River Discharge’, in the journal Geophysical Research Letters.