Influence of the Three-Gorges Reservoir on Evolution of Yangtze River bed

After the completion of the Three-Gorges reservoir,a series of changes in fluvial processes of the upper,middle and lower reaches of the reservoir will inevitably occur, causing changes in Yangtze River bed. Firstly, river mouth bars and subaqueous deltas will be formed because of the elevated base level of the tributaries at river mouths where the tributaries flow into the reservoir and its downstream area. Secondly,swing and deformation of the riverbed will occur in the upper reaches near the reservoir and banks along the reservoir when the reservoir begins to store water. Thirdly, riverbed scouring and channel deformation will happen at the downstream of the reservoir because of unmixed water flows when the reservoir sluices, which will influence seriously Wuhan city and Jinjiang, the reach of Yangtze River from Yichang city to Wuhan city.These processes in Hubei province and Chongqing municipality should be studied and calculated as soon as possible so that the countermeasures can be made promptly.