Abstract:

With the increasingly obvious eutrophication in Three Gorges Reservoir after impounding water in 2003，more importance was attached to Nonpoint Source (NPS) pollution control.Resting on the ecoenvironment investigation in 2004 and 2005，characteristics of NPS pollutant influx and cause of the pollutants were studied for Three Gorges Reservoir and its upstream watershed (Three Gorges region).Administrative strategies for the pollution were also discussed.As a result，NPS contributes much more than point source in the total pollutant influx.Concerning the spatial distribution，upstream rivers take a dominant proportion.As to the nutrient behavior in the eutrophication，the effect of nitrogen on the water is mainly through dissolved nitrogen.In contrast，the effect of phosphorus is through particles.In view of the occurrence of NPS pollutant，four main characteristics are addressed.The vulnerable ecosystem and improper land use firstly aid a lot to the soil erosion and pollutant transfer.Furthermore，rapid developing rural economy and backward farming technology increase the risk of NPS pollution.Combined with practical situation of Three Gorges region，particular strategies are finally put forward including partitioned area management，treatment project implementation，ecoeconomy development and cultivating administration.

Key words: Three Gorges Reservoir/ nonpoint source pollution/characteristics/ strategy