Application of Fixed-Wing UAV-Based Photogrammetry Data for Snow Depth Mapping in Alpine Conditions

Abstract

UAV-based photogrammetry has many applications today. Measuring of snow depth using Structure-from-Motion (SfM) techniques is one of them. Determining the depth of snow is very important for a wide range of scientific research activities. In the alpine environment, this information is crucial, especially in the sphere of risk management (snow avalanches). The main aim of this study is to test the applicability of fixed-wing UAV with RTK technology in real alpine conditions to determine snow depth. The territory in West Tatras as a part of Tatra Mountains (Western Carpathians) in the northern part of Slovakia was analyzed. The study area covers more than 1.2 km2 with an elevation of almost 900 m and it is characterized by frequent occurrence of snow avalanches. It was found that the use of different filtering modes (at the level point cloud generation) had no distinct (statistically significant) effect on the result. On the other hand, the significant influence of vegetation characteristics was confirmed. Determination of snow depth based on seasonal digital surface model subtraction can be affected by the process of vegetation compression. The results also point on the importance of RTK methods when mapping areas where it is not possible to place ground control points.

Methodology and Results of Staged UAS Photogrammetric Rockslide Monitoring in the Alpine Terrain in High Tatras, Slovakia, after the Hydrological Event in 2022

“…The research carried out in the locality of the Small Cold Valley confirms the results of the research by several authors, e.g., [53][54][55][56][57][58]. UAS-SfM photogrammetry was verified as a suitable and accurate method for monitoring geological processes and phenomena, such as morphological changes on debris cones, landslides, river erosion, rock falls, and other geohazards, even in highly complex high-mountain terrain.…”

Uncrewed Aerial Systems in Water Resource Management and Monitoring: A Review of Sensors, Applications, Software, and Issues

“…Unmanned aerial systems can prove to be a boon. Te main applications in the cryosphere include DSM generation [154], change detection, snow depth estimation [65,237,238], tundra vegetation mapping [239,240], ice-wedge polygon mapping [241], and so on.…”

UAS remote sensing applications to abrupt cold region hazards

“…A study in the Tatra Mountains located in the northern part of Slovakia used a fixed wing UAS and SfM to create snow depth maps of an avalanche prone slope to assess likelihood of slope failure. The authors emphasized the importance of using post process kinematic (PPK) or RTK techniques to reduce GPS errors and create accurate snow depth models (Masný, Weis, and Biskupič, 2021). Adams, Bühler, and Fromm (2018) also used UAS photogrammetry and SfM processing to compare visible and near infrared (NIR) spectra in avalanche terrain to improve snow depth model accuracy.…”

“…The studies discussed in this review are mostly research focused and rarely address specific needs for hazard risk communication and response. For example, because avalanche risk assessment is not only informed by UAS snow depth products, the required accuracy is sensitive to the usage context (Masný, Weis, and Biskupič, 2021). Similarly, the need to post-process data, such as GPR and LiDAR, limits their usefulness for transportation professionals making real-time decisions (McCormack and Vaa, 2019).…”