Extent of sediment concentration trends associated with climate and human factors across global rivers

Abstract

Abstract Suspended sediment concentration (SSC) is a key indicator of river ecosystems, influencing aquatic habitat quality, biogeochemical cycling, reservoir sustainability, and the persistence of downstream coastal land. Despite its global significance, long-term assessments of SSC trends have been limited in spatial scope. Leveraging > 88,000,000 satellite-derived SSC estimates, we analyzed trends over a 38-year period (1984–2022) across > 200,000 river segments globally. Our analysis reveals significant SSC trends in one-third of rivers, with 27% exhibiting declines and 7% showing increases. Basins with more widespread declining SSC trends are in temperate and arid regions and the extent of change is primarily associated with dam regulation and forest recovery. In contrast, increasing trends are concentrated in tropical basins, where deforestation and high rainfall causes erosion. These findings highlight the value of a spatially and temporally coherent, global riverine SSC database for documenting and pinpointing environmental change in unmonitored rivers.