Impact of incoming runoff and sediment on sediment deposition along the Chongqing reach

When the Three Gorges Reservoir operates at the normal water level of 175 m,the Chongqing reach which is at the fluctuating backwater area will have the dual characteristics of reservoir and natural river.They will present a trend of cumulative sedimentation with the lapse of operating time.According to the statistic analysis of the long term hydrological observation data from Cuntan Station in the Yangtze River and Beibei Station in Jialing River,the sediment transported into the Three Gorges Reservoir has reduced significantly in recent years.At the same time,with the implementation of the cascade development plan of the Jinsha River and the upper reaches of Jialing River,the effect of sediment-retention of large-scale reservoirs in the upstream will appear gradually,and the sediment from the Chongqing reach will also be further reduced.All of this will lessen the sedimentary rate and deposition amount of the Chongqing reach,and reduce their side bar deposition.Meanwhile,it will increase the availability of the storage capacity of the Three Gorges Reservoir and benefit the comprehensive exploitation of the shoreline and water resources of the Chongqing reach.