| 引用本文: | 娄保锋,周正,苏海,卓海华.鄱阳湖营养水平关键指标时空分布特征及适宜控制标准.湖泊科学,2023,35(3):897-908. DOI:10.18307/2023.0311 |
| Lou Baofeng,Zhou Zheng,Su Hai,Zhuo Haihua.Temporal and spatial characteristics of key indicators of nutritional level and control standards in Lake Poyang. J. Lake Sci.2023,35(3):897-908. DOI:10.18307/2023.0311 |
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| 摘要: |
| 本文研究2018—2020年鄱阳湖水质及营养水平关键指标——叶绿素a、总磷、总氮浓度时空特征，采用分位值法与压力-响应关系法等研究氮磷基准和适宜的控制标准。结果表明，2018—2020年鄱阳湖水质以Ⅳ类为主，超标污染物为总磷和总氮。近3年鄱阳湖处于“中偏富”营养水平，叶绿素a浓度均值为7.6 μg/L，总磷浓度均值为0.070 mg/L，总氮浓度均值为1.30 mg/L。所有水域在年内皆会出现富营养时段；年内各月份皆有水域处于富营养水平。总磷、总氮浓度枯水期高于丰水期；8月总磷浓度最低，8—9月总氮浓度最低。叶绿素a浓度较高的季节为秋季，尤以9月最高，9月全湖叶绿素a浓度均值和中位值分别为16和12 μg/L，皆超中-富营养界限值10 μg/L，原因在于9月“五河”退水与仍处汛期的长江干流顶托导致流速减缓。叶绿素a浓度较高的水域为入湖河流尾闾水域、浅水湖湾、碟形湖（如南湖村、金溪咀、南矶山、蚌湖等）。鄱阳湖平均N/P比为52，相对于藻类繁殖需求而言，氮、磷皆处于过量状态，总磷宜作为首要控制因子，总氮控制亦应考虑。鄱阳湖总磷基准范围为0.029~0.054 mg/L，总氮基准范围为0.50~0.81 mg/L。考虑当前水污染防治、社会经济发展所处的阶段和现实，目前鄱阳湖适宜的总磷控制标准在0.050~0.100 mg/L之间，适宜的总氮控制标准在1.00~1.50 mg/L之间。另外，对入湖河流控制断面，总磷控制标准应严于目前的0.20 mg/L，并建立适宜的总氮控制标准。 |
| 关键词: 鄱阳湖 营养水平 氮磷 基准 |
| DOI：10.18307/2023.0311 |
| 分类号: |
| 基金项目:国家重点研发计划项目（2019YFB2102905）资助。 |
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| Temporal and spatial characteristics of key indicators of nutritional level and control standards in Lake Poyang |
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Lou Baofeng, Zhou Zheng, Su Hai, Zhuo Haihua
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Monitoring and Scientific Research Center of Yangtze River Ecology and Environment Administration, Wuhan 430010, P. R. China
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| Abstract: |
| This work studied the key indicators of nutritional level of Lake Poyang in recent three years (2018-2020) including temporal and spatial characteristics of Chl.a, total phosphorus (TP) and total nitrogen (TN). The results showed that the water quality of Lake Poyang was mainly Class Ⅳ, and the pollutants exceeding national standard were TP and TN. The average concentrations of Chl.a, TP and TN during 2018-2020 were 7.6 μg/L, 0.070 mg/L and 1.30 mg/L, respectively. Presently, Lake Poyang is under medium-to-rich nutrient level. All the lake area had eutrophication periods in the year, and in all months of the year, there were regions that were eutrophic. The concentrations of TP and TN in dry seasons were higher than those in wet seasons. TP concentrations were the lowest in August and TN concentrations were lowest during August-September. The season with higher Chl.a concentration was mainly from September to November, especially in September when the mean and median values of Chl.a concentrations were 16 μg/L and 12 μg/L, exceeding the mesotrophic limit value of Chl.a, indicating that the whole lake was eutrophic. The reason was that the velocity of water in the lake slowed down due to the retreat of the "Five Rivers" in September and the mainstem of the Yangtze River still in the flood season. The waters with high Chl.a were the tail waters of rivers entering the lake, shallow lake bay and dished lake waters, such as Nanhu village, Jinxizui, Nanjishan, Banghu lake, etc. The ratio of nitrogen and phosphorus in Lake Poyang was 52, and both of TN and TP were excessive for algae production. TP should be controlled as a key point, and TN control should also be paid attention too. The reference of TP of Lake Poyang is in the range of 0.029-0.054 mg/L, and TN is in the range of 0.50-0.81 mg/L. Considering requirement of water pollution prevention and social and economic development, it is suggested that TP control objective of Lake Poyang is set in 0.050-0.100 mg/L, and TN in 1.00-1.50 mg/L. In addition, for the control section of rivers entering the lake, TP control objectives should be more strict than current 0.20 mg/L, and an appropriate TN standard should be properly established. |
| Key words: Lake Poyang nutrient level nitrogen and phosphorus criteria |
