Land surface changes in response to touristic activity in the fragile, high-mountain environment: a case study of Vinicunca (Rainbow Mountain) in Andes, Peru

This study contributes to the topic of land surface degradation due to touristic activity by documenting examples of trail impacts related to initial trail development and high-intensity visitor usage. Our observations are based on a case study from the tropical Andes - Peru’s Rainbow Mountain (also named Vinicunca or Montaña de Siete Colores), which became a world-renowned tourist destination in recent years (after 2015/2016). The topic is important, as such high-mountain settings are very fragile, and degradation can occur rapidly – with long-term repercussions, as these landscapes tend not to recover quickly.

The main objectives of the study were to: (1) characterise and map different types of impacts related to direct visitor pressure, (2) document and evaluate activities aimed at limiting degradation while enhancing visitors’ experience, and (3) propose a conceptual model of trail functioning in the tropical high-mountain environment. Data were collected using ground-based surveys, unmanned aerial vehicle (UAV) and high-resolution satellite images.

Eight processes were responsible for transformation of the land surface: (1) trampling, (2) abrasion/shearing by visitors and service animals, (3) transformation of water and sediment circulation, (4) water erosion, (5) freeze-thaw cycles, (6) dry-wet cycles, (7) aeolian activities, and (8) mass movements. The five main trail impacts clearly visible in the landscape just after 1–2 seasons of intensive recreational use were: trail widening, trail incision, formation of braided trail networks, development of muddy sections, and development of informal (visitor-created) trails.

The hiking path was characterised by a width below 2 m and a low incision (<0.1 m incision on 80% of its length). The equestrian path was much wider (up to 17 m) and slightly more incised (<0.3 m incision on 69% of its length). The width of the multi-use path was up to 24 m. We suggest that the location of the trail in relation to the main geomorphological elements of the landscape (valley bottom vs slopes) and trail alignment to the terrain gradient have an essential impact on trail functioning and degradation. Specifically, trail sections routed through flat terrain and without lateral restrictions tend to widen and develop muddy sections, while sections routed parallel to steep slopes were prone to incision. Trails transverse to the terrain gradient were better drained but often developed into several parallel paths.

Undertaken trail management aimed to reduce negative visitor impacts and improve their safety and satisfaction. Successful measures included hardening the trail tread and marking the trail edges, which limited visitor dispersion and stabilised trail conditions. Partially successful actions involved installing artificial drainage (only partly preventing muddy section development) and providing separate paths for pedestrians and equestrians. After this change, the pedestrian trail was narrow and stable, but the equestrian path continued to degrade. Attempts to change visitor traffic patterns by relocating parking and abandoning a section of the trail were unsuccessful, as the new road and parking, and a new additional trail segment further degraded the landscape. Moreover, geomorphological processes continued to transform the abandoned trail section.

This study was funded by National Science Centre, Poland, project 2021/43/B/ST10/00950