UAV‑Based Infrared Thermography for Characterising Unstable Slopes in a Mining Area

Rockfalls and slides pose significant hazards in open-pit mines; however, widely adopted tools for non-contact geomaterial characterisation and slope monitoring are still lacking.This study investigates the application of unmanned aerial vehicle-mounted thermal infrared cameras (UAV-IRT) for observing, detecting, and inferring material parameters in active surface mining environments. A multitemporal UAV‑IRT campaign was conducted to acquire thermal imagery across the full diurnal temperature range, from daily maxima to minima. Results from the thermal images collected at the Jezeří open-pit mine in Czechia showed that cooling indices can be used to estimate material properties, such as porosity, demonstrating strong potential for integration into geotechnical slope-design systems.On the one hand, the analysis also highlights limitations, particularly when target features receive intense solar radiation, which can reduce the reliability of parameter detection. On the other hand, UAV-based infrared thermography is shown to be a practical tool for characterising surface materials in areas affected by mass wasting—a step toward the development of automated material‑parameter detection algorithms, applicable to both artificial and natural slopes, with the overarching goal of improving safety.