UAV applications to assess short-term dynamics of slow-moving landslides under dense forest cover

Abstract

The paper presents a methodology to rapidly assess and map the landslide kinematics in areas with dense vegetation cover. The method uses aerial imagery collected with UAVs (Unmanned Aerial Vehicles) and their derived products obtained from the structure from motion technique. The landslide analysed in the current paper occurred in the spring of 2021 and is located in Livadea village from Curvature Subcarpathians, Romania. This landslide affected the houses in the vicinity, and people were relocated because of the risk of landslide reactivation. To mitigate the landslide consequences, a preliminary investigation based on UAV imagery and geological-geomorphological field surveys was carried out to map the active parts of the landslide and establish evacuation measures. Three UAV flights were performed between 6 May and 10 June using DJI Phantom 4 and Phantom 4 RTK UAVs (Real-Time Kinematic Unmanned Aerial Vehicles). Because it is a densely forested area, semi-automated analyses of the landslide kinematics and change detection analysis were not possible. Instead, the landslide displacement rates and the changes in terrain morphology were assessed by manually interpolating the landmarks, mostly tilted trees, collected from all three UAV flights. The results showed an average displacement of approximately 20 m across the landslides, with maximum values reaching 45 m in the transport area and minimum values below 1 m in the toe area. This approach proved quick and efficient for rapid landslide investigations in a densely forested area when fast response and measures are necessary to reduce the landslide consequences.

Forensic assessment of landslides induced by environmental changes in Sumedang, Indonesia, an important step for the future disaster prevention

“…Detailed spatial topography will be derived, and key surface features of the conditions before and after the landslide will be analyzed. The previous study has demonstrated the advantage of using UAV for landslide investigations [21][22][23]. There is proof that landslide movements can be mapped with centimeter accuracy using time-series UAV images [24].…”

Lithological classification by PCA-QPSO-LSSVM method with thermal infrared hyper-spectral data

“…[75][76][77] For inaccessible field areas, the DJI Phantom 4 RTK (DJI-P4RTK) UAV can be used to obtain ultra-high spatial resolution images, and the entire process is not restricted by geographical conditions. 78,79 In addition, satellite data of the study area in the same temporal phase, such as Aster and WorldView-3, can be acquired. 65,[80][81][82] These images are used to obtain the exposed lithology of the study area and further validate the classification results.…”

Terraced Landscapes as NBSs for Geo-Hydrological Hazard Mitigation: Towards a Methodology for Debris and Soil Volume Estimations through a LiDAR Survey

“…High nega Finally, the volume trapped into terraces was estimated by computing the difference between the actual surface and the interpolated one. The computation of the DoD (DEM of differences) is widely used to characterize the Earth's changing surface [44][45][46]. The calculation was repeated for every single identified slope.…”