Effects of ground-contacting gear on trail surface deformation from trampling

• Impacts of different gear on trail erosion were assessed by experiments. • Advanced 3D topographic methods like SfM-MVS photogrammetry enabled detailed quantification of soil deformation patterns. • Barefoot trampling results in minimal footprint depth and lateral expansion compared to shod trampling. • The use of trekking poles significantly increased lateral soil spread, underscoring their potential to exacerbate trail erosion when combined with other gear. Pedestrian traffic represents a significant factor contributing to soil surface erosion along trails. During mountain hiking, different types of ground-contacting gear, such as footwear and trekking poles, may have varying impacts on trail erosion. Utilizing recent advancements in three-dimensional (3D) topographic measurement, including structure-from-motion multi-view stereo (SfM-MVS) photogrammetry combined with light detection and ranging (Lidar), we conducted experiments simulating trail erosion through repeated walking with different gear sets, including trekking poles, trekking shoes, trail running shoes, and barefoot. The repetitive traversal over the experimental plot with different gear resulted in distinct deformation patterns on the soil surface. Employing SfM-MVS photogrammetry partially supported by Lidar, we captured and quantified 3D morphological changes in the experimental trail surface, providing a comprehensive analysis of the amount and spatial patterns of erosion with a centimeter-level accuracy. While the depth of footprints remained relatively consistent across different footwear types, we found that the hardness of footwear significantly influences the lateral extent of soil deformation. Specifically, trekking shoes caused the greatest lateral soil displacement, while barefoot walking had the least impact. Furthermore, the inclusion of trekking poles in the experiment demonstrated an additional effect, enhancing the lateral spread of soils. These findings provide deeper insight into the complex dynamics of trail erosion caused by pedestrian activities and offer valuable guidance for effectively managing actual trail surface erosion in natural environments.