Abstract: A hydrodynamics and water quality regulation model based on gate-pump joint operation was built with Mike11. Multi-objective function was designed and the effect of regulation schemes was evaluated by grey multi-objective optimization algorithm. The hydrodynamics and water quality are positively correlated with the hydrodynamics of adjacent external river,but negatively related with the distance from adjacent external river. The model is applied tothe Zhongshun large polder in Pearl River Delta and demonstrated that the water power and quality is bad in general. In view of this, five schemes of gate-pump joint operation were put forward to improve the hydrodynamics and water quality in the study area, and an optimum scheme was selected using grey multi-objective optimization algorithm. The present model is verified to well demonstrate the comprehensive effect of hydrodynamic and water quality improvement under different regulation schemes of gate-pump joint operation, and offers reference for similar tidal river networks.

Key words: Mike11, gate-pump joint operation, control of hydrodynamics and water quality, multi-objective optimization, tidal river network, Zhongshun large polder