Shaping the peaks: Human-driven geomorphological transformations in high-elevation landscapes

High-altitude landscapes are highly sensitive to human activities. In fact, anthropogenic interventions often modulate the intensity and rate of natural geomorphological processes, leading to significant and sometimes irreversible changes to landscapes and ecosystems. This study examines the effects of human activities on the landscape in two distinctive areas affected by human agency at least since historical times: the Central Italian Alps (Cancano, Livigno and Passo dello Stelvio) and the Central Apennines. These regions showcase the effects of pastoralism, infrastructures, historical warfare and tourism. Our approach integrates remote-sensing analyses, investigation on archival records and field surveys to provide a comprehensive assessment of human impact on mountain regions. At Cancano, the construction of dams for reservoirs modified natural hydrological and geomorphological systems, tuning water flow, altering sedimentary budgets and ultimately influencing the evolution of fluvial landforms. In Livigno, the development of ski slopes, bike trails, and tourism infrastructure triggered a major change of local land cover, increased surface runoff, erosion, and slope instability. Analysis of historical aerial imagery reveals the expansion of erosion-prone zones, while archival photos highlight the stark contrast between past and present landscapes. Passo dello Stelvio has been exploited for skiing since 1950s thus leaving a marked overprint on the landscape. Moreover, World War I trenches, bomb craters, and fortifications have disrupted natural landforms in an high-sensitive area, while tourism infrastructure and the construction of the road continue to affect slope stability and erosion. In the Central Apennines, the introduction of pastoral land use centuries ago is the major anthropogenic forcing that shaped landscapes. The creation of numerous sheep tracks has contributed to soil loss, reduced water infiltration, and increased erosion. Additionally, the construction of dry-stone walls, terraces, corrals has significantly altered the geomorphology, modified surface hydrology and influencing slope stability. This study, funded by Italian Ministry of University and Research through PRIN project “GEOTRes”, underscores the diverse and enduring impacts of human activities on high-altitude geomorphological processes, also suggesting difference in their onset. Today, high-altitude ecosystems are particularly fragile to ongoing climate change and anthropogenic modifications of landscapes represent a further factor menacing the stability of surfaces and tuning geomorphic processes.