珠江虎门河口营养盐的分布特征及其环境影响

Distribution Characteristics of Dissolved Nutrients and Their Environmental Effect in the Pearl River Estuary

摘要: 基于珠江虎门河口2016年枯季(1月3~10日)水文水质多要素同步观测数据，采用Pearson相关分析和主成分分析等方法研究河口动力及氮磷营养盐的潮周期变化，并探讨虎门河口营养盐的环境影响机制。结果显示，大、小潮观测期间氨氮浓度变化范围为0.59~2.06 mg/l，硝酸盐氮浓度变化范围为1.20~3.54 mg/l，亚硝酸盐氮浓度变化范围为0.14~0.49 mg/l，磷酸盐浓度变化范围为0.025~0.063 mg/l，且垂向平均浓度分别为1.20 mg/l，1.84 mg/l，0.32 mg/l和0.04 mg/l，揭示虎门河口动力驱动下氮磷营养盐的潮周期差异显著。水文要素盐度和含沙量亦随潮汐涨落变化较大，而水温无明显潮周期变化，且各因子对氮磷营养盐的影响机制不同。外海水团对氮营养盐的稀释混合作用强于磷营养盐，而悬浮泥沙对氮营养盐以吸附作用为主，对磷营养盐吸附与解吸附作用共存。研究结果将为珠江口的污染治理及生态修复提供科学依据。

Abstract: This study aims to investigate the tidal variations of hydrology and dissolved nutrients, based on extensive field measurements during January 3~10, 2016 in the Humen outlet of the Pearl River estuary, and to indicate the nutrient dynamics. The concentration of NH4 varied from 0.59~2.06 mg/l, 1.20~3.54 mg/l for NO₃, 0.14~0.49 mg/l for NO₂, and 0.025~0.063 mg/l for PO₄ during the sampling time, which demonstrates a significant difference in tidal changes. Salinity and suspended sediment fluctuated with tides, and no big tidal difference was found in water temperature. The role of marine waters on the diluting-mixing process of nitrogen was stronger than that on phosphorus. Compared with nitrogen, phosphorus was scarce in this study, and was a limited factor. The results enable us to develop effective coastal management and to benefit from more focused studies in the functioning of ecological health.