Abstract: Due to the reservoir regulation of the Three Gorges Project (TGP), the water and sediment load flowing into the Jingjiang river reach downstream of,TGP have undergone significant changes both in the process and in the amount. Conspicuous erosion, which leads to river regime changes in some locations, has occurred in the Jingjiang river channel, consequently affecting the embankments, bank protection works along both sides, river regulation projects, and the stability of river bed at different levels in the long-run, and further affecting the flood control, navigation, ecology, environment and the integrated function of the river in these areas. In this paper, the movable bed model test of Changjiang River Flood Protection Model was adopted to study the changing process, the amount and distribution,of scouring and silting of the Jingjiang river course from Yangjianao to Haoxue at the initial operation stage of TGP. Based on this understanding, the tendency of river changes were predicted as well. The obtained research results may be taken as technical references for the planning and designing of river harnessing and river regime control projects in this river course.

Key words: Changjiang river flood protection model  ,  Three Gorges Project  ,   downstream reservoir  ,   erosion and sedimentation  ,  river regime