Abstract: Water blooms are prone to break out in reservoir when dams are built up. Adjusting the reservoir operation is a practical approach to alleviate its impact on eco-environment in the short term. With the water blooms in the Three Gorges Reservoir as a background and in accordance with the actual operation of the reservoir, we designed 9 feasible emergency scheduling cases through mathematical numerical simulation. For each case, we analyzed the characteristics of flow upstream of the dam during water level drawdown, and expounded the effects of reservoir operation on the water blooms in the purpose of seeking the optimum reservoir operation plan to curb water blooms in the Three Gorges Reservoir. Results suggest that the operation in case 5 has obvious effect by reaining a large discharge in the initial period of the operation and a consequent big exchage rate.

Key words: Three Gorges Reservoir, water bloom, operation mode