Satellite Observations Reveal Widespread Color Variations in Global Lakes Since the 1980s

Abstract

The color of lakes is an essential indicator of the local ecological state, and the corresponding changes can reflect the physical and biochemical processes of lakes. However, worldwide changes in lake color and their drivers remain largely unknown. Here, we analyze the long-term color distributions and changes of 67,579 lakes worldwide from 1984 to 2021 by utilizing 32 million consistent satellite observations. Blue lakes (<495 nm) were primarily located in high-latitude and high-elevation areas. Green lakes (495–560 nm) were more prevalent in densely populated middle-latitude regions, while most red and yellow colors (≥560 nm) were located in the Southern Hemisphere. Our findings reveal distinct temporal patterns of lake color changes, with the majority of global lakes shifted toward shorter wavelengths. This phenomenon is more common in Warm Temperate and Boreal zones. Lake color changes are closely linked to basin vegetation conditions, population, water volume change, and lake area. Our study provides essential references for monitoring the ecological status of global lakes, further supporting the sustainable development of water resources in the future.