Analysis of Sediment Nutrient Pollution Characteristics of Enclosed Fish Ponds in Baiyangdian Lake

In order to solidly promote the governance and protection of the ecological environment of Baiyangdian Lake, taking the bottom sediment of the enclosed fish ponds in three areas of Baiyangdian Lake as the research object, the plane and vertical distribution characteristics of nutrients such as total nitrogen (TN), total phosphorus (TP) and organic matter in different layers (0~60cm) in the bottom sediment were analyzed with Nemerow index method, and the pollution degree of sediment in each area was evaluated. The results showed that the TN concentration of the fish pond bottom sediment in the Shaochedian area was 1020.0mg/kg~2101.7mg/kg, the TP concentration was 267.7 mg/kg~787.2 mg/kg, the organic matter content was 2.7%~9.5%, and the pollution degree of the fish pond was mainly light and moderate. The TN concentration of the fish pond bottom sediment in Zaolinzhuang area was 502.3 mg/kg~1996.7mg/kg, the TP concentration was 292.1mg/kg~5465.3mg/kg, the organic matter content was 2.9%~10.8%, the pollution degree of the fish pond was mainly light and moderate. The TN content of the fish pond bottom sediment of the fish pond in the Wanloudian area was 470.8mg/kg~2075.0mg/kg, TP concentration was 128.0mg/kg~705.8mg/kg, the organic matter content was 3.4%~9.6%, and the pollution degree of fish pond was mainly moderate and heavy. From the perspective of the vertical distribution of pollutants, the organic matter content and TN of the bottom sediment of the fish pond in each area showed a gradual decreasing trend from the surface layer (0~10cm) to the bottom layer (50~60cm), and the removal of the surface sediment was the key to the reduction of endogenous pollution in the fish pond in Baiyangdian Lake, while the TP had no obvious regularity.