Landslide monitoring using geotechnical, UAV, GNSS and MTInSAR instrumentation

Many mountainous villages have been struck by landslides in Western Greece due to growing urbanization and uncontrolled land use in landslide prone areas, without considering the engineering geological environment. The presence of the tectonically highly sheared and weathered geological formations of the alpine basement (such as flysch) and the intense geomorphological relief, strongly contribute to the periodically induced instability phenomena mainly triggered by heavy rainfalls and extreme meteorological events. The current research combines long-term monitoring of the parameters connected to the landslide activity with the real-time kinematics observation in a dense-populated mountainous village located in the Region of Epirus in Greece. The landslide movements evolve very low velocity values at different depths; thus, the landslide cases can be characterized as complex and "extremely slow". The long-term monitoring is carried out by several in-place and portable inclinometer probes that permit the detailed observation of subsurface displacements for an extended period. In addition, GNSS measurements, very high-resolution multitemporal interferometry (accompanied with the installation of corner reflectors) and Unmanned Aerial Vehicle (UAV) photogrammetric surveys are used for the monitoring of surface deformation. All instrumentation is installed in the wider area of the landslide zone and one of the main goals of this approach is to combine long-term monitoring of the parameters connected to the landslide activity with the observation of the landslide kinematics in real-time.