Abstract: Location selection is an important scientific issue in the research and construction of water ecological barrier. Considering the characteristics of river-type reservoir with various inflow modes and large topographic fluctuation, we presented a location selection method for ecological barrier of river type reservoir based on flux analysis with the removal function of non-point source pollution of water ecological barrier. Using this method, we examined the ecological barrier location in the Three Gorges Reservoir area of China. The results showed that the role of ecological barrier for water in the study area could not be brought into full play according to the design plan of 100 m width along the coast of the Three Gorges Reservoir area. The zone of optimal function accounted for 11% of the design area, and ineffective zone accounted for 10% of the design area. 79% of the total nitrogen and 93% of the total phosphorus were concentrated in the area accounting for 21% of the total ecological barrier area and entered the reservoir. According to the flux of pollutants and their process of flow and flux, we extracted the confluence area of pollutants with high flux and area with high pollutant concentration. Based on the protection target, the ecological engineering measures to reduce the total pollutants and ensure the standard reaching of pollutant concentration were carried out respectively. This method, with full consideration of the influence of terrain on pollutant flux and classification of the key protected areas in water ecological barrier, could effectively solve the problem of location design of water ecological barrier in river-type water.

Key words: ecological barrier, non-point source pollution, location design, river-type reservoir, flux analysis