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根据获取的唐山湾海域1995-2012年25个站位现场观测数据和资料,基于主成分分析(PCA)对人类活动影响下唐山湾海域营养盐及其结构变化进行研究.结果表明:在人类活动影响下,近20年唐山湾海域无机氮(DIN)呈现明显的增长趋势,磷酸盐(PO_4~(3-)-P)、硅酸盐(SiO_3~(2-)-Si)则呈下降趋势;平均N:P由1995年的3.0增长到2012年的26.0,而Si:N则呈下降趋势,海水营养盐结构发生了明显的变化.据此利用主成分分析识别水质变化,共提取了2个主成分,第1主成分以DIN、NO_3~--N、NH_4~+-N、PO_4~(3-)-P和NO_2~--N为代表,解释了71.5%的方差;第2主成分以叶绿素(Chl a)和SiO_3~(2-)-Si为代表,解释了21.8%的方差,说明唐山湾水质变化主要与DIN、PO_4~(3-)-P因子变化关系密切.2个主成分得分揭示了人类活动影响下唐山湾水质年际变化趋势,即由1995-2005年开发前及开发初期的N限制向2007年开发后的P限制转变.人类活动影响下唐山湾海域营养盐及其结构已经发生了明显变化,这种变化尤其是无机氮含量的增加,需要引起高度关注.
Based on the observed data and data from 25 stations in Tangshan Bay from 1995 to 2012, the nutrient components and their structural changes in Tangshan Bay under the influence of human activities were analyzed based on principal component analysis (PCA). The results showed that in the human activities In the recent 20 years, the inorganic nitrogen (DIN) in Tangshan Bay area showed a clear trend of increase with the decreasing trend of PO 4 - (3 -) - P and SiO 3 - (2 -) - Si ; Average N: P increased from 3.0 in 1995 to 26.0 in 2012, while that of Si: N decreased and the structure of nutrients in seawater changed significantly. Based on this, the principal component analysis was used to identify the water quality changes and 2 The principal components, the first principal component is represented by DIN, NO_3 ~ - N, NH_4 ~ + -N, PO_4 ~ (3 -) - P and NO_2 ~ --N, explained 71.5% of the variance; The components of chlorophyll (Chl a) and SiO 3 - (2 -) - Si represent the variance of 21.8%, indicating that the changes of water quality in Tangshan Bay are closely related to the changes of DIN and PO 4 ~ (3 -) - The principal component score reveals the interannual trend of Tangshan Bay water quality under the influence of human activities, that is, from the N limit before pre-development and early development in 1995-2005 to the post-development P limit change in 2007. The impact of human activities Nutrients Tangshan Bay and its structure has undergone significant changes, which in particular increase the inorganic nitrogen content, need to attract attention.