Extreme weather and heavy rainfall are increasingly presenting new challenges for operators of critical infrastructure. Flood protection systems in particular, such as dykes and earthen embankments, must function reliably to protect settlements, transport routes and industrial facilities. Researchers in Austria are therefore investigating how satellite-based radar technology can enable continuous monitoring of these systems in the future.
Infrastructure monitoring from space
In the ‘HoSMoS’ research project, the AIT Austrian Institute of Technology is analysing how dams can be monitored over the long term using satellite data. The basis for this is radar data from the Sentinel-1 Earth observation mission, operated by the European Space Agency.
The focus is on so-called InSAR technology (Interferometric Synthetic Aperture Radar). It enables the measurement of minute movements of the Earth’s surface over extended periods. This allows changes to structures or terrain features to be detected at the millimetre level.
This opens up new possibilities for operators of flood protection systems: instead of relying solely on spot surveys or local sensors, an entire section of a dam can be monitored regularly from space.
Early warning system for structural damage
The technology is based on satellites transmitting radar waves to Earth. Certain surface structures – such as edges, metallic components or paved surfaces – reflect these signals with particular stability. By comparing repeated measurements, changes can be analysed precisely.
Such data can, for example, show whether a dam is slowly subsiding or whether material movements are occurring. Causes may include washouts inside the structure or changes in the groundwater level. If such movements are detected early, remedial measures can be initiated before the stability of the structure is compromised.
The challenge of vegetation
However, flood protection structures present a particular difficulty: many earthen dams are overgrown with vegetation. Plants and trees reduce radar reflection and make it difficult to identify stable measurement points.
Researchers are therefore investigating various solutions. In addition to alternative satellite systems, artificial reflectors – known as corner reflectors – could also be installed on dams. These technical elements reflect radar beams particularly reliably and increase measurement accuracy.
Greater safety for smaller rivers
Whilst large rivers are often already extensively monitored, the focus is increasingly turning to smaller watercourses. It is precisely there that flood protection structures can be crucial, even though they are often monitored less intensively.
Satellite-based monitoring systems could play an important role in risk management here in future. As radar data is archived long-term, historical trends can also be traced and structural changes analysed over many years.
In view of increasing extreme weather events, the combination of space technology, remote sensing and traditional structural monitoring could become a key component in protecting critical infrastructure and ensuring more resilient flood prevention.
