Research on distribution characteristics of inorganic nitrogen in Yundang Lake: For prevention and control of the red tide

Water samples were collected from the 8 sampling points in Yundang Lake, Xiamen City from June to December 2012. The water temperature as well as concentration of ammonia nitrogen, nitrate nitrogen and nitrite nitrogen in these water samples were measured, the spatiotemporal distribution characteristics of inorganic nitrogen was revealed, the influence of water temperature and precipitation on distribution of each kind of inorganic nitrogon was explored. Aim of this study is to provide basic information for prevention and control of polluton and red tide of Yundang Lake. The results show that the average concentration of inorganic nitrogen is 2.03 mg • L^-1 in the inside lake, 1.950 mg • L^-1 in the outside lake. Inside lake pollution is more serious, the average concentration of ammonia nitrogen was 1.360 mg • L^-1, accounting for 68.30% of inorganic nitrogen which average concentration is 1.990 mg • L^-1. Self-purification capacity of the lake is weak. Water temperature has a less influence on the distribution of inorganic nitrogen, precipitation has a greater corresponding influence.