Preliminary Research on Hydrodynamic Dispatch Method of Algal Blooms in Three Gorges Reservoir Bays

Spring algal happened in the bays area frequently after Three Gorges Reservoir’s impoundment. Algal bloom is closely related with nutrients, light, temperature and flow velocity. This paper carried out preliminary research on algal blooms hydrodynamic control method by optimizing reservoirs dispatch on main and tributary channels. Making use of software MIKE 21, a Xiangxi River-Three Gorges Reservoir integrate hydrodynamic numerical model has been established, and a series of conditions have been simulated and studied. The result shows that if Three Gorges Reservoir operates alone, velocity at Xiangxi River mouth is less than 0.05m/s, and if Xiangxi Reservoir operates alone, velocity at Xiangxi River mouth is larger than 0.05m/s in wet year. It implies that Three Gorges Reservoir’s water level change has little to do with improvement of tributaries’ velocity, but reservoir in main and tributary channels dispatch together can improve the velocity obviously, which can control algal bloom in tributary bays.