九龙江河口区主要污染物时空变化特征

根据九龙江河口区近30年的历史监测资料和2010年2个航次的现场调查资料,分析了该海域表层海水中无机氮(DIN)、活性磷酸盐(DIP)、化学耗氧量(COD)和石油类浓度的年际变化特征和平面分布变化特征,并应用富营养状态指数(EI)对海水水质进行评价与分析.结果表明,近30年,DIN、DIP年均浓度持续上升,COD年均浓度呈“W”状小幅波动趋势,石油类年均浓度先缓慢增加再降低;DIN浓度平面分布呈由西至东递减的特征,不同年份的DIP浓度平面分布有所差别,而COD和石油类浓度平面分布呈由湾内、西海域向湾外递减的趋势;海水EI呈不断加速升高的趋势,海水水质富营养化程度急剧恶化;受九龙江径流影响,高富营养化海域主要分布在九龙江北、中、南港和南溪入海口附近.所得的主要污染物浓度年际变化特征和平面分布变化特征等将为实施入海污染物总量控制奠定坚实基础.

Spatiotemporal variations of main pollutants in Jiulongjiang Estuary

Based on the survey data,including 2 cruises in 2010,obtained from recent 30 years in Jiulongjiang Estuary,the annual variations and spatial distribution of DIN,DIP,COD and petroleum hydrocarbon were analyzed and eutrophication index(EI) were applied to assess the eutrophication conditions.The annual concentration of DIN and DIP tended to rise in recent 30 years while the petroleum hydrocarbon concentration increased slowly at first and then declined and COD fluctuate in small amplitude.DIN was higher in the west than the east of the estuary with variations of DIP annually while COD and petroleum hydrocarbon concentration were high in the inner estuary and lower in the western waters of Xiamen harbor and in the outer estuary.The increasing EI for 30 years indicates that the seawater quality was in a state of deteriorating.The most eutrophic areas were located in the north,middle and south part of Jiulongjiang Estuary and at the Nan Xi opening,which suggests that it was resulted from the great input of Jiulongjiang River.All data,annual variations of pollutants with their horizontal distribution,should lay a solid foundation for establishment of total amount control of pollutants to the sea.