Impact of river training on the hydraulics of Shenzhen river

We present a study on the impact of river training on Shenzhen River hydraulics by an integrated three-dimensional numerical hydrodynamic model. The model is verified against field data and shows good agreement with the observed hydrodynamics; wetting and drying of inner Deep Bay tidal flats are successfully simulated. The model simulations show that river training has drastically altered the hydraulics of Shenzhen River. Tidal propagation in the river has changed from a damped tidal oscillation to a more standing wave character with less amplitude damping. Tidal current is reduced by about 50%. Vertical salinity stratification and gravitational circulations are formed within the trained river in the dry season. The bottom upstream residual current in the two-layered residual circulation strongly suggests the input of sediment from Deep Bay and sediment trapping in the river.