【作者】 姜胜；

【导师】 杨宇峰；

【作者基本信息】 暨南大学 ， 水生生物学， 2006， 博士

【摘要】 2004年1月至12月，在广州海域东四口门（虎门、蕉门、洪奇门和横门）共布设4个采样断面进行入海通量调奇。2003年8月至2004年8月，在广州海域布设17个调查站位进行营养盐和重金属水样的采集。采样频率为每月1次。分析项目有要有氨氮（NH₄-N）、亚硝态氮（NO₂^--N）、硝态氮（NO₃^--N）、活性磷酸盐(PO₄^3--P)、硅酸盐(SiO₃^2--Si)、化学需氧量（COD）、Hg、Zn、Cd、Pb、Cu、As及水温、盐度、溶解氧（DO）等环境因子。 根据时段通量计算方法估算出东四口门主要污染物入海通量为：DIN126.50×10⁴t／a，NH₄⁺-N5.02×10⁴t／a，NO₂-N 15.11×10⁴t／a，NO₃^--N106.34×10⁴t／a，PO₄^3--P 4.30×10⁴t／a，COD178.66×10⁴t／a，Hg18.75t／a，Zn5029.21t／a，Cd241.00 t／a，Pb471.23 t／a，Cu1564.05t／a，As2403.19 t／a。其中，各主要污染物在虎门的入海通量最高，其次为蕉门、洪奇门，横门最少，其变化特点为丰水期较高，枯水期较低。与1985年、1995年相比，污染物入海通量明显增加。受珠江流域T农业发展和生态环境不断恶化等的影响，各污染物入海通量与径流量成极显著正相关关系：DIN、NO₃^--N、PO₄^3--P、COD、Hg、Cd、Pb和As等入海通量与浓度成显著正相关关系。 广州海域DIN、PO₄^3--P和SiO₃^2--Si年平均值分别为1.63mg／L、0.043 mg／L和2.59mg／L。DIN中以NO₃^--N（66.55％）为主，NH₄⁺-N（20.19％）次之。同国内外河口海湾相比，DIN和SiO₃^2--Si含量明显偏高，而PO₄^3--P则居于中流水平。受来自东四口门工农业废水和城镇生活污水的影响，其平面分布基本上表现为湾内高于湾外，近岸处高于远岸处。相关分析表明，DIN和SiO₃^2--Si与盐度无相关关系，表现为非保守行为。 广州海域DIN∶P、Si∶P和Si∶DIN比值的平均值分别为92.6、69.7和0.79。以Dortch等（1992）和Justic（1995）提出的营养盐化学计量限制标准来衡量，广州海域浮游植物生长受控于单一营养盐限制因子的可能性为氮1.06％、磷88.36％、硅3.70％。由此表明，磷是限制广州海域浮游植物生长的主要限制因子。 广州海域重金属Hg、Zn、Cd、Pb、Cu和As的年平均值分别为0.042μg／L、24.57μg／L、0.54μg／L、1.21μg／L、9.87μg／L和4.23μg／L。各重金属的平面分布特征不尽一致，Hg、Zn和Cu为湾顶低、湾外高；Cd为锯状波动；Pb为湾内高，湾外低；As在湾内、湾外均为高值，在海域中部较低。重金属元素、营养盐和环境因子之间的相关分析和聚类分析结果表明，Hg、Zn、Cd、As与盐度成正更多还原

【Abstract】 Material fluxes were surveyed in the four sections of the four east outlets （Humen, Jiaomen, Hongqimen and hengmen） once a month from January, 2004 to December, 2004. Seawater samples for studying the nutrients and heavy metals were collected from 17 stations in the Guangzhou sea area once a month from August, 2003 to August, 2004. The monitoring parameters included ammonium （NH₄⁺-N）, nitrite （NO_<sup>--N）, nitrate （NO₃^--N）, phosphate (PO₄^3--P), silicate (SiO₃^2--Si), chemical oxygen demand （COD）, mercury （Hg）, zinc （Zn）, cadmium （Cd）, lead （Pb）, copper （Cu）, arsenic （As）, water temperature, salinity and dissolved oxygen （DO）.According to the method of period fluxes, the fluxes of major pollutants were estimated from the four east outlets. The results showed that the fluxes of DIN, NH₄⁺-N, NO₂^--N, NO₃^--N, PO₄^3--P, COD, Hg, Zn, Cd, Pb, Cu and As were 126.50×10⁴t/a, 5.02×10⁴t/a, 15.11×10⁴t/a, 106.34×10⁴t/a, 4.30×10⁴t/a, 178.66×10⁴t/a, 18.75t/a, 5029.21t/a, 241.00t/a, 471.23t/a, 1564.05t/a and 2403.19t/a, respectively. The seasonal variation pattern of the fluxes represented higher values in the flood period than that in the drought period. The highest flux was recorded in Humen, then in Jiaomen and Hongqimen, successively, the lowest in Hengmen. Compared with the fluxes in 1985 and 1995, these of all major pollutants increased remarkably in the investigated period. The correlations between major pollutant contents, the flows and their fluxes from the four east outlets were analyzed. The results showed that there were very significant correlations between their fluxes and flows were, and significant corretations between fluxes of DIN, NO₃^--N, PO₄^3--P, COD, Hg, Cd, Pb, As and their contents.In the Guangzhou sea area, the annual average concentrations of dissolved inorganic nitrogen （DIN）, phosphorus (PO₄^3--P) and silicate (SiO₃^2--Si) were 1.63 mg/L, 0.043 mg/L and 2.59 mg/L, respectively. Amongst them, 66.55% DIN was NO₃^--N and 20.19% DIN was NH₄⁺-N. Comparing with other estuaries around the world, the concentrations of DIN and SiO₃^2--Si were much higher while the concentration of PO₄^3--P was of average level. DIN, PO₄^3--P and SiO₃^2--Si decreased gradually from inner bay to outer bay, from nearshore to offshore. This distribution pattern was mainly a result of the industrial discharge, domestic and agriculture sewage from the east four outlets. Due to the terrestrial sewage from更多还原