Abstract
Lake Titicaca in South America is highly sensitive to climatic variability, making it particularly vulnerable to climate change and raising concerns about long-term drying. Fluctuations in lake-water-levels (LWLs) can trigger cascading impacts across the downstream Titicaca-Desaguadero-Poopó-Salares (TDPS). This study evaluates the dependence of Lake Titicaca’s water level on air temperature and precipitation using a rainfall-runoff model to estimate river inflows, combined with a lake routing model (LRM) to simulate water-level variations. Future projections of LWLs were developed using extreme precipitation and evaporation rates and downscaled climate scenarios, from which temperature trend were incorporated into the LWLs modeling. Results suggested that, even with no significant changes in precipitation, a continued increase in evaporation of approximately 3 mm per year associated with rising air temperatures in the whole catchment could cause Lake Titicaca to become a terminal lake by around 2050 and permanently terminal lake after 2085. A decrease in precipitation or further increases in evaporation would likely accelerate this transition due to the reduction in lake surface area. Such changes could have major consequences for the TDPS system and increase the likelihood that Lake Poopó becomes permanently dried-up.