Determination of soil deformation caused by mechanical harvesting equipment using unmanned aerial vehicle data

The physical impacts of mechanical timber extraction machines (skidders) on forest soil were evaluated using Unmanned Aerial Vehicle (UAV)-based digital imagery. The research was conducted in the Saros Forest Enterprise Chief, where field measurements (manual ruler method) and UAV data were comparatively analyzed. Wheel rut depths were determined after skidding operations performed at two slope classes (0–20% and 20–50%) and during the 5th, 10th, and 15th passes of the skidder. The results indicated that the rut depths calculated from UAV imagery were highly consistent with those obtained from manual measurements. It was observed that rut depths were greater on steeper slopes (20–50%) and increased with the number of machine passes. In addition, soil properties such as bulk density and hygroscopic moisture showed varying trends with slope and pass number; bulk density tended to increase in low-slope areas while decreasing in steep slopes, whereas hygroscopic moisture increased in low slopes but decreased in higher slopes. The study demonstrated that UAV-based techniques provide a reliable approach for monitoring soil deformation caused by forest operations. The proposed methodology can enable the prediction of potential environmental impacts of mechanical harvesting equipment and contribute to the development of more sustainable forest production planning. Furthermore, this method has potential applicability for evaluating the environmental effects of other mechanized forestry systems used in Turkey.