Abstract: The eutrophication of tributary is one of the main water environmental problems caused by the water storage of the Three Gorges Reservoir. According to the changes of water quality and the eutrophication status of the tributaries of the Three Gorges Reservoir during the different historical impoundments, it is shown that the hydrodynamic conditions of the tributary are further weakened after the Three Gorges Reservoir enters the normal operation from the experimental storage stage. The ability to disperse pollutants into the river decreases significantly,and the water quality of the reservoir bay gradually becomes worse. The tributaries show moderate and eutrophication levels. The overall performance during the year is higher in spring than in autumn. From the characteristics of eutrophication evolution of the tributaries in the Three Gorges Reservoir area, the change of the hydrodynamic conditions of the reservoir bay from the river state to the lake reservoir state is the main driving force for its eutrophication. The nutrient input is the material basis.

Keywords：Three Gorges Reservoir；tributary；eutrophication；hydrodynamic conditions

(Journal of China Institute of Water Resources and Hydropower Research, Vol. 16, No. 6, 2018)