Flood-driven jet flow and sedimentary regime in a river-dominated estuary

Sediment dynamics under floods are critical for estuarine morphological evolution. A two-dimensional coupled hydrodynamic/sediment transport numerical modeling was adapted to investigate the flood-driven jet structure and resultant sedimentary regime in a river-dominated estuary, Modaomen Estuary, Pearl River Delta, China. The results show that flow velocity of flood exhibits Gaussian distribution transverse direction shows linear decreasing trend longitudinal direction. Moreover, distinct zonation, including zone establishment (ZOFE) established (ZOEF), detected. ZOFE core area high turbidity strong erosion provided sufficient sediments ZOEF, where sediment diffused settled. Due settling lag, diffusion deposition areas were larger than those jet. Estuarine geomorphology regulates shape jet, which an asymmetry configuration with main body located at west side bifurcated estuary. Tidal play crucial role altering range diffusion, especially Increased intensity has little effect on erosion/deposition pattern, but significantly increases magnitude seaward current velocities bed level changes, as well sedimentation.