Landslide monitoring
One possible measure to protect against landslides is the monitoring of landslide-prone slopes. Today, the FOEN uses state-of-the-art methods, such as radar interferometry, to monitor slopes. This makes it possible to identify landslide masses and determine the magnitude of landslide movements.
Observations
Comprehensive monitoring of landslide-prone slopes requires observation of the following factors:
- Meteorological conditions
The main triggering mechanism for slope processes is prolonged and intense precipitation. It is therefore important to take meteorological conditions into account when monitoring landslide-prone slopes. - Hydrological conditions
The amount of precipitation that has already fallen, as well as groundwater levels, provide information on possible destabilisation of landslide-prone slopes. - Ground movements
The development of sliding velocities can be monitored through measurements. In addition to traditional measurement methods, increasingly sophisticated satellite-based methods, e.g. distance measurement using radar interferometry, are being developed.
Radar interferometry
With this method, satellites transmit radar waves towards the Earth's surface where they are reflected. This enables highly precise distance measurements between the satellite and the Earth's surface. If a slope is moving, the distance between the satellite and the Earth's surface changes from one measurement period to the next. The measuring instruments detect this difference and display it accordingly in satellite images.
This method provides new monitoring possibilities in uninhabited areas where no other measuring networks exist. Radar interferometry is therefore particularly suitable for slopes that were previously stabilised by permafrost but are now thawing and beginning to move as a result of climate change. The data are particularly useful when combined with geomorphological information.