Lower Meuse Paleoflood Record Reveals NAO-Driven Decadal to Multi-Centennial Variability

A central challenge in assessing climate-driven flood regimes is constructing long-term paleoflood records with sufficient temporal resolution to identify both short- and long-term variability. To address this, we performed grain-size and X-ray fluorescence scanning analyses on two cores from paleochannels in the Lower Meuse (the Netherlands). The downcore ln(Zr/Rb) ratio proves to be a reliable grain-size proxy, allowing reconstruction of flood-related sediment input variations. We find the flood intensity record displays a ∼300-year cycle, synchronous to the North Atlantic Oscillation record at this band. Importantly, the recurring quasi-decadal (7–10 years) oscillation indicates an active and stationary high-frequency flooding regime despite significant climatic and human impacts in the Late Holocene. This study advances paleoflood methodology by demonstrating that paleochannel infills provide valuable archives for reconstructing flood histories across multi-annual to millennial intervals, thus enhancing our ability to track hydrological responses to climate variability across multiple timescales.