抚仙湖入湖河流面源污染雨季特征

Characteristics of Non-Point Source Pollution in Rivers Entering Fuxian Lake during the Rainy Season

摘要: 为研究抚仙湖入湖流域农业污染对入湖水质的影响，通过实验监测尖山河流域雨季时不同形态的氮、磷以及化学需氧量(COD)的质量浓度，对入湖河流氮、磷、COD在2021年雨季时月变化和氮、磷、COD，2020年、2021年年监测分布特征进行分析。结果表明：2020年尖山河雨季入湖水体总氮的质量浓度为3.88~2.70 mg/L，平均值为3.36 mg/L，硝态氮平均浓度为2.03 mg/L，占总氮的59.73%，是最主要的赋存形态；氨氮平均浓度为0.50 mg/L，占总氮的15.02%，总磷的质量浓度为0.26~0.21 mg/L，平均值为0.23 mg/L，正磷酸盐平均质量浓度为0.21 mg/L，占总磷的89.67%，COD质量浓度为10.33~6.33 mg/L，平均值为7.93 mg/L。2021年尖山河雨季入湖水体总氮的质量浓度为2.60~0.94 mg/L，平均值为1.91 mg/L，硝态氮平均浓度为0.16 mg/L，占总氮的10.43%，氨氮平均浓度为1.12 mg/L，占总氮的57.86%，是最主要的赋存形态；总磷的质量浓度为0.28~0.19 mg/L，平均值为0.25 mg/L，正磷酸盐平均质量浓度为0.13 mg/L，占总磷的51.33%，COD质量浓度为11.00~5.00 mg/L，平均值为8.33 mg/L。整体较2020年呈现明显的下降趋势。

Abstract: In order to study the influence of agricultural pollution on the water quality of Fuxian Lake wa-tershed, the mass concentrations of different forms of nitrogen, phosphorus and chemical oxygen demand (COD) in the rainy season of Jianshan River watershed were monitored experimentally. The monthly changes of nitrogen, phosphorus and COD in the rainy season of 2021 and the distribution characteristics of nitrogen, phosphorus and COD in 2020 and 2021 were analyzed. The results showed that the mass concentration of total nitrogen in the water entering the lake in the rainy season of Jianshan River in 2020 was 3.88~2.70 mg/L, with an average value of 3.36 mg/L. The average concentration of nitrate nitrogen was 2.03 mg/L, accounting for 59.73% of total nitrogen, which was the main occurrence form. The average concentration of ammonia nitrogen was 0.50 mg/L, accounting for 15.02% of total nitrogen. The mass concentration of total phosphorus was 0.26~0.21 mg/L, with an average value of 0.23 mg/L. The average mass concentration of or-thophosphate was 0.21 mg/L, accounting for 89.67% of total phosphorus. The mass concentration of COD was 10.33~6.33 mg/L, with an average value of 7.93 mg/L. In 2021, the mass concentration of total nitrogen in the water of Jianshan River in the rainy season was 2.60~0.94 mg/L, with an average of 1.91 mg/L. The average concentration of nitrate nitrogen was 0.16 mg/L, accounting for 10.43% of total nitrogen, and the average concentration of ammonia nitrogen was 1.12 mg/L, ac-counting for 57.86% of total nitrogen, which was the most important form of occurrence. The mass concentration of total phosphorus was 0.28~0.19 mg/L, with an average of 0.25 mg/L. The average mass concentration of orthophosphate was 0.13 mg/L, accounting for 51.33% of total phosphorus. The mass concentration of COD was 11.00~5.00 mg/L, with an average of 8.33 mg/L. The overall trend is significantly lower than that in 2020.