The construction of ski runs with artificial snowmaking in mountain areas changes natural water circulation and leads to activation of erosion and accumulation processes. To recognise this relationship, we selected a small catchment in the Gubałowskie Foothills, the Inner Carpathians, where 17% of the area is covered by the ski runs. The main purpose of our study was to: (i) present morphology and morphometrics of channels that drain and do not drain ski runs; (ii) recognise differences in statistical relationships between channel morphometrics in both types of channels; and (iii) estimate morphometric changes due to erosion and accumulation processes in selected channels. To identify these changes, we conducted geomorphological mapping of step pool channels, statistical analyses, DEM (Digital Elevation Model), and DOD (DEM of Difference) analyses (based on point clouds from 2016 and 2023). In order to identify the effect of ski run construction on channel morphology, we divided channels into two groups: 1) stream channels that do not drain ski runs, and 2) stream channels that drain ski runs. Results showed that the routing of drainage from the ski runs to the channels leads to a significant intensification of erosion in the channels with the maximum deepening, up to 2.6 m. It also changes the dominant geomorphological processes in the channels. Fluvial processes are beginning to dominate slope processes. The described changes occurred already 8 years after the opening of the ski station and reveal the scale of land degradation connected to artificial snowmaking in ski resorts.

Ski tourism’s popularity is driving a rise in the number of ski resorts. This study aims to present the impact of ski infrastructure on soil erosion processes on the example from a small catchment in the Gubałowskie Foothills in southern Poland, where landscape changes before (since 1879) and after the construction of the ski station (2007) were presented. The analyses of changes in flow accumulation, slope morphometry, and drainage ditches were conducted in the test area. Quantitative analyses were performed using repeated DEMs derived from LiDAR survey and detailed geodetic measurements, complemented by geomorphological mapping done in the field. The study has revealed that the ski infrastructure has not only directly transformed the hillslope by flattening and constructing escarpments (up to 3 m high) but has also created alternating patterns of erosion and accumulation. In the test area, the drainage ditch was poorly designed. It was filled by materials (0.1–0.5 m), and two new outlets formed. The escarpment of the analyzed ski run has been diminished by 0.5 m. An alluvial fan (0.1 to 0.22 m thick) has developed on the flattened surface below the escarpment with drainage ditch outlets. This fan is eroded by subsurface flow that creates a piping system. The gully below the alluvial fan has retreated upslope, accelerated by subsurface erosion. This study enables the presentation of hillslope adjustments and processes in response to the new conditions caused by ski infrastructure. Such results may support more effective land management in regions changed by ski infrastructure.