Impacts of land reclamation projects on hydrodynamics and morphodynamics in the highly altered North Branch of the Changjiang Estuary

Abstract The estuary is highly dynamic and sensitive to external internal forcing. We examine a chain reaction of hydrodynamic morphodynamic responses series land reclamation projects during the period 1997 2017 in North Branch Changjiang Estuary through Digital Elevation Model (DEM) comparison numerical simulation by Finite Volume Community Ocean (FVCOM). results show that tidal amplification was further strengthened artificially reduced channel volume middle upper segments due implementation several large-scale land-reclamation first stage (1997–2007), siltation turn promoted increased flows with flood dominance. In second (2007–2017), relaxed narrowing project at lower segment waterway improvement dredging works segments. Contemporary erosion almost balanced accretion because weakening dominance over ebb flows. Spatiotemporal variation patterns response estuarine engineering vividly mirrored change simulated bed shear stress areas (decreased) underwent severe (accretion). These findings highlight again feature tide-dominated estuaries importance tools management.