Digital Terrestrial Stereo-Photogrammetry for Monitoring Landslide Displacements: A Case Study in Recoaro Terme (VI)

Monitoring landslides and potentially unstable areas is of primary importance for the landslide risk assessment and for the identification of the proper mitigation measures. The advanced topographic techniques, such as aerial drone and laser scanner survey, are very good alternatives to the classical survey with total topographic station, because they reconstruct the distribution of surficial displacements with high precision and high resolution. Digital terrestrial photogrammetry and stereo-photogrammetry may represent a low-cost option, which allows long-lasting measurements at fixed time steps. Moreover, at the cost of a lower resolution, it may provide denser distributed measurements on large areas and the reconstruction of the 3D surface of the landslide. Finally, it permits the monitoring of superficial displacements from a temporal sequence of digital images, captured from two or more fixed cameras over a certain period. This paper presents the preliminary results obtained by applying this technique for the displacement monitoring of a landslide close to Recoaro Terme municipality (Vicenza). The setup of the hardware and the procedure of the stereo-photogrammetric method will be briefly introduced. The factors affecting the accuracy and precision of this method will also be discussed.