Eutrophic investigation and assessment on backwater reaches of several typical branches of three Gorges Reservoir at 135m water level

Through the eutrophic investigation and assessment on backwater reaches of three typical branches, such as:Zhuyi-river,Meixi-river and Daning-river ,at 135m water level in March ,2004, the different distribution models of the trophic status of Backwater reaches of the main branches of the 135m water level in this season are grasped.