Reservoir sedimentation alters sediment continuity in regulated river basins, affecting both reservoir storage capacity and downstream river and coastal systems. This study presents a basin-scale framework for reconstructing long-term sediment supply and reservoir sedimentation in the Ebro River Basin (Spain) using publicly available erosion datasets, empirical sediment delivery ratios and reservoir sedimentation observations. Three sediment supply datasets (GloSEM, RUSLE2015 and WaTEM/SEDEM) were combined with sediment delivery ratios and reservoir trapping functions to reconstruct sediment continuity patterns across the basin. Model calibration was performed using reservoir sedimentation records covering approximately 95% of the basin area. The framework reproduces the main spatial and temporal patterns of sediment accumulation observed in the basin and allows the definition of plausible sediment supply scenarios. Results indicate that current sediment fluxes at the basin outlet are reduced by more than 90% relative to natural conditions due to reservoir trapping. Most reservoirs experience moderate storage losses, although several reservoirs are projected to undergo severe long-term sedimentation. The proposed approach provides a transferable basin-scale sediment assessment methodology for supporting sediment management under data-limited conditions.
Granados et al. (Fri,) studied this question.