Researchers unlock tool to monitor abandoned sites

Researchers at the University of Nottingham in the United Kingdom have developed a remote monitoring tool to help authorities manage safety in recently abandoned coal mines.

The tool, which can be used on a worldwide scale, uses satellite radar imagery to capture millimetre-scale levels of changes in terrain height, which can be used to monitor and forecast groundwater levels.

This technology can also be used to monitor changes in geological conditions deep below the earth’s surface in former coal mining areas.

The researchers found that when deep mines are closed, the groundwater that was previously pumped to the surface to make mining safe, can rise again until it is restored to its natural level via a process called rebound.

The rebound water needs careful monitoring as it often contains contaminants that can cause water pollution to drinking water supplies, flooding, land uplift and reactive geological faults.

The study lead and PhD student David Gee said the use of satellite radar and interferometric synthetic aperture radar (InSAR) could lead to the development of a cost-effective method to model groundwater rebound from surface movement changes.

“InSAR measurements, when combined with modelling, can assist with the characterisation of the hydrogeological processes occurring at former mining sites,” Gee said.

“The technique has the potential to make a significant contribution to the progressive abandonment strategy of recently closed coalfields.”