Sanxianhu Lake's water quality and quantity relates to the drinking water in Nanxian County of Hunan province and the surrounding area's strategic security. For the watershed protection planning and policy making, surveys have been carried out to analyze Sanxianhu Lake water environment situation and diagnose its ecological environment problems. Results show that Sanxianhu Lake average concentration of total phosphorus is 0.18 mg/L and average concentration of total nitrogen is 1.26 mg/L, both meeting the V class of water quality. Compared with other major domestic lakes, it follows that Sanxianhu lake < Dongtinghu Lake < Poyanghu Lake < Taihu Lake in terms of total nitrogen, and Poyanghu Lake < Dongtinghu Lake < Sanxianhu Lake < Taihu Lake in terms of total phosphorus. Moreover, the polluted effect in sediments caused by total nitrogen is higher than that by total phosphorus. Compared with major domestic lakes in sediments, Dongtinghu Lake < Sanxianhu Lake < Poyanghu Lake < Taihu Lake in total nitrogen values, and Sanxianhu Lake < Poyanghu Lake < Dongtinghu Lake < Taihu Lake in phosphorus values. Sanxianhu lake is suffering from pollution problems including agricultural nonpoint source pollution, sediment deposition, internal pollution release risk, free range livestock and the fertilized pond fisheries.

Sanxianhu Lake  /  water  /  sediment  /  polluted amount