Climate‐Change Projections of Flow Distribution Across the Rhine Delta

Abstract We project climate‐driven changes in flow and sediment partitioning across the Rhine delta using a hybrid one‐dimensional model informed by two‐dimensional sediment‐partitioning data. Simulations spanning 150 years and 540 km show a continued shift of discharge toward the Waal branch, while the effects of historical interventions gradually diminish. Climate impacts on flow division emerge around 2050 and intensify thereafter: by 2150, the IJssel is projected to convey approximately up to 17% less discharge under low‐flow conditions, whereas the Waal may receive up to 6% more. Although hydrograph changes have limited influence on flow partitioning, they markedly increase channel‐bed erosion by coarsening the sediment flux delivered to the bifurcation region and enhanced sensitivity to shear‐stress gradients across the bifurcation. Consequently, climate forcing, particularly sea‐level rise, overtakes past interventions as the dominant driver of future flow partitioning and bed level adjustment. These results have direct implications for long‐term water management, navigation, and ecological resilience in the Rhine delta.