Abstract：As the key works for harnessing and developing the Yangtze River, the Three Gorges Project (TGP) has considerable comprehensive benefits in the flood control, power generation and navigation as well as in the improvement of the environment and ecological system, which plays an important role both in the economic-social sustainable development and implementation of the Western Development of China. After completion and operation of the TGP, the water-sand conditions of the Yangtze River will be changed and sedimentation will occur in the backwater zone at the tail of the reservoir. On the other hand, clean water discharge will bring long-term and long-distance erosion to the channel of middle & down streams, which will lead to changes in sedimentation of the Dongting Lake and relationships between the river and the lake. In addition, for the middle & down streams, new problems will occur such as flood safety of river regime control, levees and bank protection works as well as the navigation. Therefore, special studies, further observations and reinforcements shall be carried out. How to give full play to TGP's role of environmental & ecological preservation and improvement shall be taken into consideration, and relevant measures shall be taken to minimize its negative impacts. Prevention and treatment of water pollution shall be strengthened to protect the water environment of Changjiang River basin. In accordance with the principle of "developing in protection and protecting in development", development and protection of the Yangtze River shall be accelerated to make its important contribution to the economic-social sustainable development of China.
2005, Vol. 23 
