Seventy years of slope modification in the Rhaetian Alps: Assessing the results of human activities

High-mountain areas are particularly fragile and vulnerable to rapid transformations resulting from high-relief energy and the significant dynamics of natural processes. Human activity in the mountains may contribute to the development of diverse morphodynamic zones. The main aim of the study was to identify the long-term results of human impact on ski slopes in the Rhaetian Alps (Italy). The identification of changes on the Carosello3000 and Mottolino ski slopes was carried out on the basis of the historical aerial photos from 1947 and orthophotos from 2003, 2007, 2012, 2019, and 2021 as well as fieldwork done in 2024. Over the whole study period of 18 years, 19.1% of the Carosello3000 slope and 9.6% of the Mottolino slope were devoid of dense vegetation. In 2021, 36.1% of the Carosello3000 study area was without dense vegetation; the value for the Mottolino study area was 19.5%. The research confirmed higher erosion potential of the Carosello3000 slope. Between 1947 and 2021, forest expansion by 51.5% has been confirmed on the Carosello3000 ski slope, while on the other hand, fragmentation of the forest cover was visible locally. The research has shown significant changes in the Carosello3000 and Mottolino study areas between 1947 and 2024. The changes are mainly a result of the construction of tourist infrastructure such as hiking, bicycle, and ski trails and the creation of drainage ditches. The construction of tourist infrastructure may contribute to a significant modification of the relief transformation and an increase in zones susceptible to erosion.