The effect of skiing on soil, hydrology and erosion hazard in the ski area of Sölden, Tyrol, Austria

In July and August 1999, we investigated the influence of skiing on the catchment hydrology and soil (erosion) in the surroundings of Sölden, Tyrol, Austria. Sölden is a ski village located in the Ötztal valley in between the Ötztaler and Stubaier Alps. During this research, we conducted 122 rainfall simulations, often in combination with measurements of the most important edaphic parameters. Also, continuous discharge measurements were carried out in three headwaters. We analyzed the output data, subjected them to statistical investigations in order to reveal differences and relationships and, if necessary, interpolated. With the interpolated data and the erosion- and runoff model EUROSEM we investigated where the soil is sensitive to rill erosion. It appears from the analyses that skiing only indirectly leads to compaction of the soil (via vegetation damage) but directly leads to a lowering of the soil moisture content, which may cause vegetation stress and damage. The vertical conductivity and the porosity of the soil are not affected by skiing. However, skiing increases the chance of overland flow, which, under circumstances with low vegetation cover, can lead to soil erosion. This is supported by the model results and field observations, which show the artificial soils without vegetation cover to be vulnerable to soil erosion. We recommended that the vegetation cover should be kept sufficiently high as to protect the soil from compaction and to minimize the erosion hazard. When the present policy of the skiing companies in the area is maintained, they sufficiently secure sustainability