Anita Bernatek‐Jakiel

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 in 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) are 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 aerial 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 with 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 (0.1–0.22 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.

Studying soil pipes is a methodological challenge that needs improvement in detection methods in order to better recognize the role of piping erosion in land degradation and hillslope hydrology. This study explores electromagnetic induction (EMI) and electrical resistivity tomography (ERT) in order to identify soil pipes. The study was conducted in a mountainous area (the Bieszczady Mountains, SE Poland) under a temperate climate, where pipes develop in silty‐clayey soils. In the plot area, eight profiles were measured by the conductivity meter at different depths and then interpolated to present apparent electrical conductivity (EC a ). Also, six ERT profiles were carried out using the Wenner‐Schlumberger electrode configuration. The EC a values measured by EMI are not very diversified, suggesting its lower sensitivity to changes in the EC a , whereas the EC a values measured by ERT are characterized by greater fluctuation, that is, better detection possibilities. ERT has revealed soil pipes as zones of higher electrical resistivity (ER >268 Ωm) than their surroundings (characterized below pipes by ER <105 Ωm) underlying the air filling of pipes (ER >427 Ωm), whereas EMI has revealed its higher sensitivity to water content. The EMI results have shown the lowering of the water table in the lower part of the slope, perhaps because of the drainage by a complex pipe network. EMI allows quick measurements of EC a providing information on water content, and thus indirectly soil pipes, but, it cannot delineate individual pipes. Only the integration of geophysical methods supported by field recognition provides an effective method to detect soil pipes.