湛江湾及其附近海域近5年海水中氮、磷变化趋势研究

Research on Nitrogen and Phosphorus VariationTrendin Zhanjiang Harbor and Its Near Waters in Recent Five Years

根据2011~2015年湛江湾海水质量调查数据,对该海域中的无机氮、氨-氮、硝酸盐-氮、亚硝酸盐-氮以及活性磷酸盐的浓度变化进行了研究。结果表明：活性磷酸盐呈明显上升趋势,2015年较2011年平均浓度增加了1倍;2015年无机氮的年平均浓度比2011年略有增加,增加的主要因素为亚硝酸盐和氨氮,而硝酸盐的浓度低于2011年。根据近5年的监测数据,湛江湾海水中无机氮年平均浓度最高为2013年,活性磷酸盐年最高浓度为2015年。N、P的原子比值可以表征水体接收营养盐输入负荷的结构特征,2011~2015年间湛江湾海水中N/P比值范围在4.02~9.88之间。2011年C_（DIN）/C_（PO4-P）的比值范围为4.19~14.62之间;2012年为2.26~19.46之间;2013年为6.31~31.78之间;2014年为3.15~26.12之间;2015年为2.04~13.17之间;五年间站位1#、11#、12#、13#、14#的N/P比值范围在11.10~14.24之间,接近浮游生物的生长繁殖的营养盐结构,具有赤潮暴发的潜在风险。应用DIN和PO_4-P值结合潜在性富营养化分类分级模式对湛江湾海域富营养化状况进行了分析,结果发现湛江湾海域在时间上处于氮中等限制潜在富营养（Ⅴ_N）。

In this paper, we conducted research onthe concentration change o{ inorganic nitrogen, ammonia nitrogen , nitrate nitrogen, nitrite nitrogen and active phosphorus in Zhan）iang Harbor based on the survey reports o{ Zhaniiang Harbor Seawater quality from 2011 to 2015.The result revealed that the annual average amount of active phosphorus appeared a clear upward trend, the average content in 2015 was doubling than that in 2011; The annual average amount of mineral nitrogen in 2015 was slightly increased than that in 2011 ,the content of nitrite and ammonia nitro- gen were the main parts of increase,while the content o{ nitrate nitrogen was lower than that in 2011. According to the monitoring data o[ the past {ive years, the annual average amount of inorganic nitrogen in 2013 was the highest in Zhan]iang Harbor, and the annual average amount of active phosphorus in 2015 was the highest. The N/P atomic ratiocouldreveal the structure of the load of water receiving nutrient inputs, a N/P atomic ratioof 4.02-9.88 was observed in Zhanjiang Harbor Seawaterfrom 2011 to 2015. The ratio of CDIN/Cpo4-P ranged between 4.19 to 14.62 in 2011, 2.26-19.46 in 2012, 6.31-31.78 in 2013, 3.15-26.12 in 2014,and 2.04-3.17 in 2015 the N/P atomic ratios in station GD192, GD193, GD194, GD198 and GD207 ranged between 11.10-14.24 in five years, which approached the nutrient structure of the growth of plankton, having a potential risk of the outbreak of red ties. This study also revealed that Zhanjiang Harbor was at the stage of medium--nitrogen--limited potential eutrophication in time trend by analyzing the condition of eutrophication in Zhanjiang Harbor, using the data of inorganic nitrogen （DIN） and active phosphates（PO4-P） which combined with classification and grading of potential eutrophication.