Do rivers get sufficient sleep—A global analysis of light pollution in rivers

Light pollution has become an increasingly prevalent environmental concern associated with urbanization. Rivers are more exposed to light pollution worldwide without sufficient sleep, which has significant adverse effects on riparian ecosystems. However, there is still a scarcity of quantification regarding the spatiotemporal variations of river light pollution (RLP) at the global scale. In this study, we proposed a light pollution index (LPI) and calculated the annual LPIs of 12,530 rivers worldwide from 2000 to 2022. The result shows that global RLP has increased rapidly, especially after 2010. Globally, the centroid of gravity of RLP has been shifting eastward annually, with a gradual southeastward trend since 2010. RLP in the world's 25 large populous countries was mainly classified into three types. This study underscores the significance of RLP that requires further research and effective communication to develop sustainable lighting practices and policies aimed at preserving riverscapes and their biodiversity.