Effects of climate change and anthropogenic pressure on water resources and ecosystem services in a high-elevation Andean socio-ecosystem (Katari basin, Lake Titicaca, Bolivia): A synthesis

Guédron S.; Acha D.; Molina-Carpio J.; Revilla C.; Domic A.I.; Molina C.; Anthelme F.; Rabatel A.; Condom T.; Espinoza J.C.; Hardy S.; Perales V.-H.; Legouill C.; Satge F.; Resongles E.; Sarret G.; Archundia D.; Hernández-Angulo L.R.; Pouilly M.; Montecino A.; Ormachea M.; Espinoza D.; Quispe N.L.; Tirado N.; Gardon J.; Soruco A.; Duwig C. · Science of the Total Environment (2026) · DOI: 10.1016/j.scitotenv.2026.182339

Resumen

Climate change and human activities are transforming socio-ecosystems worldwide, damaging the water cycle and biological diversity. This work analyzes the current state and vulnerabilities of the Katari watershed (Bolivia), a region representative of Andean socio-ecosystems. The high-elevation Puna is one of the biomes most affected by climate change in the South American Central Andes. Regional climate scenarios predict increasing warming, declining precipitation and enhanced evaporation, which are expected to increase the frequency and duration of droughts. Glaciers are rapidly retreating, and critical ecosystem components such as peatlands and lakes are impacted by global change. Anthropogenic pressure significantly compounds these challenges, accelerating system's degradation. The Katari watershed, which includes the large urban area of El Alto, faces persistent challenges due to insufficient sanitation infrastructure. The discharge of untreated effluents containing a mixture of organic matter, nutrients, metal(loid)s, and emerging contaminants like antibiotics damages the Katari - Lake Titicaca socio-ecosystems. This contamination poses potential public health risks associated with sustained exposure to environmental contaminants. Finally, the synergistic effects of climate and pollution can lead to abrupt degradation events, such as eutrophication and massive algal blooms in Lake Titicaca, threatening local biodiversity. Addressing these challenges urgently requires reducing contaminant discharge, preserving natural spaces and creating engineered buffer zones that leverage local ecological characteristics, like plant-based filtration systems, to naturally remove contaminants from water. Furthermore, advancing sustainable management requires the reinforcement of governance structures that incorporate local communities' needs and knowledge into decision-making processes, thereby fostering more resilient management systems.

Instituciones: Pontificia Universidad Católica del Perú