Insights into the influence of anthropogenic forcing on sediment dynamics in the Yellow River basin

Understanding sediment provenance within river basins is critical for deciphering sediment generation and deposition processes, promoting soil conservation, and guiding human activities. Here, we combine radiogenic Nd isotopes and zircon U-Pb ages to investigate the source-to-sink dynamics of modern Yellow River sediments from the middle to lower reaches. We also analyze the provenance of the Late Pleistocene Mangshan loess, which serves as a sediment archive of ancient Yellow River. Our findings reveal a significant shift in sediment provenance between the middle and lower reaches of the modern Yellow River. Specifically, we observe a decrease in sediment supply from the middle reaches and an increased contribution from the North China Craton (24 % for coarse components; 10 % for fine components). This stark change in sediment sources is less evidence in the Late Pleistocene, as demonstrated by the dominance of CLP-derived materials in the Mangshan loess (93 %–96.5 %). This suggests a significant shift in sediment supply to the lower reaches of the Yellow River from ancient to modern time. We propose that this temporal change in sediment provenance is most likely driven by human activities such as soil conservation practices and dam construction. Our findings offer valuable insights into the Anthropocene by highlighting changes in sediment dynamics over time.