Permanent terrestrial LiDAR monitoring in mining, natural hazard prevention and infrastructure protection – Chances, risks, and challenges: A case study of a rockfall in Tyrol, Austria

The objective of this work is the development of an integrated monitoring service for the identification and evaluation of ground surface and slope movements in the context of coal mining, the prevention of natural hazards and protection of infrastructure. The focus is set on the integration of a long-range terrestrial laser scanner into a continuous monitoring system from an engineering geodetic point of view. In the Vals valley in Tyrol, a permanently installed laser scanner was successfully operated via a web portal to monitor surface processes in the area of rockfall debris on a high-mountain slope in the summers of 2020 and 2021. This paper describes the practical benefits of this permanent laser scanning installation. In addition to the potentials of automatic data acquisition, possibilities for multitemporal analysis with respect to spatio-temporally variable changes are presented, using advanced 3D change detection with Kalman filtering. The level of detection for deformation analyses therein depends on the quality of the georeferencing of the sensor and the noise within the measured point cloud. We identify and discuss temporally variable artifacts within the data based on different methods of georeferencing. Finally, we apply our change detection method on these multitemporal data to extract specific information regarding the observed geomorphologic processes.