Monitoring dikes from space - European satellite inspects dikes

Terrafirma has launched a project to observe dikes around the IJsselmeer, The Netherlands using satellite images. Improvements in technology mean weak spots in dikes can now be detected in time, improving protection from dike failures. Terrafirma is a European project organised by ESA, the European Space Agency, involving the Dutch organisations Deltares, TNO and Hansje Brinker.

Dike monitoring 2.0

For some time now, people have been looking for an appropriate way of extending the current approach to dike inspection. The present inspection methods, which are mainly visual, are no longer adequate. The Terrafirma project is therefore using advanced satellite images to check the stability of dikes around the IJsselmeer. The equipment in the satellite measures ground motion to within a few millimetres. In this project, we will be teaming up with water management authorities to look at how information about this movement can be used to detect weak spots in dikes.

Pauline Kruiver, a consultant/researcher with research institute Deltares: ‘We look at vertical surface movement of the dike and the strip of land behind the dike. If the level of a dike or a part of a dike falls relatively quickly, that can indicate impaired stability. Measurements like this make it possible to select areas that require extra attention during dike maintenance. And we can also use the satellites to monitor the condition of a dike after improvements have been made.’

Future applications

Monitoring dikes with satellite measurements means water authorities can administer and explain their day-to-day management and maintenance work better. Against the background of climate change and the associated measures needed to prepare the Netherlands for the changes in the water regime, this information is very useful indeed for water authorities. In addition to the various applications in the Netherlands, the various possibilities abroad are also being looked at: Germany and Denmark have already shown interest.

Terrafirma is financed by ESA, the European Space Agency. The project brings together more than 30 European specialists in the field of earth observation, geology, earthquakes, hydrology, floods, and landslides. In the near future, ESA will be launching even more precise satellites, which will also fly over the Netherlands more often. ESA's Envisat satellite now passes over once every 35 days. The Sentinel satellites of the future will observe the Netherlands once every 12 days, making it possible to keep an even closer eye on the dikes.

Example satellite image ground movement