鄱阳湖区氮磷污染物分布、转移和削减特征

根据入湖污染负荷监测、调查资料和不同水文条件下流场-水质同步监测资料,应用数理统计方法,研究了鄱阳湖氮磷营养物质分布、转移和削减特征。研究结果显示:(1)总磷、总氮是影响鄱阳湖水环境质量的主要污染物,入湖污染负荷与入湖径流水量紧密正相关。(2)鄱阳湖换水周期短,水流更换频繁,氮磷污染物在湖区不会充分混合;氮磷超标水域随着水体流动,逐步向下游转移、扩散;湖水位处于消落状态,通江水道部分水域氮磷浓度超标。(3)湖相状态水环境比河相好,湖相状态一般不会出现大面积的总氮和总磷同时超标。(4)鄱阳湖水环境勉强维持Ⅲ类标准,如果出现损害环境的人类活动,脆弱的水环境将会恶化。针对这些特征提出了保护鄱阳湖"一湖清水"的对策建议。

CHARACTERISTICS OF DISTRIBUTION,TRANSFER AND SUBTRACTION OF NITROGEN AND PHOSPHORUS CONTAMINANTS IN POYANG LAKE

Based on monitoring and investigation of the in-lake pollution loads and simultaneous monitoring of flow field & water quality under different hydrological conditions,the characteristics on distribution,transfer and reduction of nitrogen and phosphorus in Poyang Lake are studied using mathematical statistics.The results show that:(1) the TP and TN are the main pollutants which affect the water quality in Poyang Lake,and there is a close positive correlation between the pollution load and the in-lake flow.(2) the TP and TN contaminants are not mix well in the lake,due to that the water exchange cycle is short.Nitrogen and phosphorus pollutants gradually transfer and diffuse to the downstream with the flow.(3) the water environment under lake state is better than that under the river state.The TP and TP generally do not simultaneously exceed the water quality standard in large area under the lakes state.(4) The water environment in Poyang Lake barely maintains the class Ⅲ standard.However,human activities have great potential to deteriorate the water environment.Finally,the countermeasures to protect the water environment quality in Poyang Lake are proposed based on the above conclusions.