摘要
对太湖污染情况进行了调查研究,全面分析了其底泥的氮污染规律.结果表明,底泥表层受人类活动影响较大,总氮含量总体超标;其第2、3、4、5层,总氮污染程度已大为降低.得出了不同保证率条件下太湖底泥总氮浓度垂向变化规律,并据此确定太湖底泥生态清淤的深度为上层40～50cm.对太湖底泥各层次总氮浓度概率分布的计算发现,它基本符合随机对数正态分布规律.提出了太湖底泥氮污染生态风险分析方法,定义了度量生态风险的指标,并计算了生态风险值,计算结果表明,太湖底泥氮污染生态风险程度较高的区域依次是五里湖、东太湖、梅梁湖南区等,此为生态清淤重点区域.
The nitrogen contamination distribution in silt of Taihu Lake is analyzed based on the sampling data. It is found that the nitrogen contamination content on the surface layer of silt is high and seriously affected by human activities. The distribution of contamination content along the silt depth exhibits sharply decrease tendency. The contamination content probability distributions along the depth of silt obey random logarithmic normal law. It is concluded that the surface silt with depth 40cm to 50cm is important to the elimination of contamination of the lake. The method for ecological risk analysis of Taihu Lake is suggested accordingly and the corresponding indexes for indicating the ecological risk are defined. The calculation result of ecological risk shows that there are five areas in the lake possessing high ecological risk in which the silt must be cleared.
出处
《水利学报》
EI
CSCD
北大核心
2005年第8期900-905,共6页
Journal of Hydraulic Engineering
基金
国家自然科学基金重点项目资助(50239030)
关键词
太湖
底泥
总氮
富营养化
生态风险
nitrogen contamination
silt
eutrophication
ecological risk analysis
Taihu Lake
