The Impact of Snow Grooming on Morphology and Erosion of Alpine Hillslopes: A Case Study from Kasprowy Wierch Ski Station in the Tatra Mountains

The rapid expansion of ski tourism and climate change-induced snow shortages have led to intensified ski run maintenance, including extensive earthworks, artificial snowmaking, and regular snow grooming. While these activities are known to cause significant land degradation, quantitative geomorphological studies, specifically on the effects of snow grooming, are limited. This study addresses this knowledge gap by quantitatively assessing the impact of snow grooming on erosion processes and hillslope morphology by comparing them with natural landforms. We achieved this by determining the spatial distribution, morphometry, and long-term persistence of studied landforms. The study area consisted of a unique ski resort at Kasprowy Wierch, which does not use artificial snowmaking or extensive earthworks. We combined detailed field mapping with the analysis of multi-temporal Digital Elevation Models (DEMs) and orthophotos from 2012, 2019, 2020, and 2023. Our methodology also included the calculation of volumetric changes using the DEM of Difference (DoD) analysis. We distinguished two groups of eroded areas, natural landforms (e.g., shallow landslides, debris flow tracks, nivation niches) and snow groomer-induced forms, which were concentrated on ski runs. Natural landforms were elongated and deeper, with higher edges, clustered along debris flow tracks, and occurred on steeper slopes (mean 26.8&deg:). They were more persistent and extensive, with a total area ranging from 3891 m&sup2: in 2012 to 3452 m&sup2: in 2023. In contrast, groomer-eroded landforms, located on gentler slopes (mean 23.4&deg:), were smaller, more angular, less persistent, and concentrated on narrower, intensively used ski run sections. Their total area decreased from 2122.71 m&sup2: to 1762.25 m&sup2: over the same period, despite an increase in their count. The volumetric analysis revealed distinct dynamics: over the long term (2012&ndash:2023), natural forms showed a total deposition of +8.196 m&sup3:, while groomer-eroded forms experienced total erosion of -2.070 m&sup3:. During an extreme rainfall event in 2020, natural landforms experienced vast erosion of -163.651 m&sup3:, nearly five times greater than the -33.765 m&sup3: observed on snow groomer-eroded landforms, demonstrating their greater susceptibility to high-magnitude events. Importantly, a comparison with other studies reveals that the scale of erosion from snow grooming is relatively small compared to the severe impacts of artificial snowmaking. Our findings are relevant for managing protected areas, such as Tatra National Park, where the focus should be on mitigating anthropogenic impacts to preserve natural processes, which in turn implies that the development of new ski infrastructure should be prohibited.