Andean Lakes: a proposal for lake districts

The Andes, the world’s longest mountain system (8500 km), harbour important headwater systems that constitute crucial water resources for South America. Their complex topography significantly influences climate and hydrology. The Andes have a wide diversity of aquatic environments, with >5000 lakes (>0.1 km ², permanent and excluding constructed reservoirs) with different morphometry, including the largest and the deepest in South America (Titicaca and Viedma, respectively). We applied a grouping analysis based on available systematised information to delimit different lake districts along the Andes. More than 60% of the surface area of all Andean lakes is concentrated in only 9 large lakes, and >80% of the lakes are <1 km ². This analysis proposes 11 lake districts, including 2 in the North Andes, 6 in the Central Andes, and 3 in the South Andes. Each lake district is described based on the different morphologies, geological origins, climatic factors, and available limnological information. We believe this study will benefit not only scientists but also decision-makers and stakeholders working in integrated water resource management in a region subject to climate change and socioeconomic inequalities.