Abstract: In an attempt to optimize the dispatching mode of the Three Gorges Reservoir (TGR) in flood season, we analyzed the variations of inbound and outbound sediment discharge after the impoundment of TGR based on measured data, and preliminarily investigated into the dynamic operation mode of “storing clear water and releasing muddy water” in flood season in terms of sediment. Since the impoundment of TGR, inbound sediment discharge has reduced by a large margin in flood season; in particular, since the operation of Xiluodu reservoir and Xiangjiaba reservoir, sediment concentration in TGR in flood season (June to September) has been smaller than those in May and October of demonstration stage. Meanwhile, accounting for over 90% of the annual value, sediment outflow in main flood season mainly concentrated in one or two large sand peaks. In the near future, the dynamic operation mode of “storing clear water and releasing muddy water” in flood season allows for sediment deposition.

Key words: Three Gorges Reservoir, operation mnode in flood season, storing clear water and releasing muddy water, dynamic operation, sedimentation