摘要
采用经典的Mann-Kendall非参数统计检测方法对洞庭湖湿地1991—2009年的水环境重要参数进行了变化趋势分析。结果表明,电导率、COD、BOD5、总氮、总磷、悬浮物呈显著上升趋势,色度、大肠杆菌、硝态氮、铵态氮呈不显著上升趋势,溶解氧呈显著降低趋势,pH、透明度呈不显著降低趋势。可见,洞庭湖湿地水质在逐步下降。突变趋势中,各参数突变时期及次数存在明显差别。除色度有1突变点位于显著信度线(p=0.05)与极显著信度线(p=0.01)之间,其余参数突变点均位于显著信度线之间。以色度和悬浮物突变最频繁,总氮和硝态氮变化最为平缓,其余参数居中。从各参数突变发生的时间可知,水质突变主要发生在1992—1998年。其次,对影响洞庭湖湿地水环境变化的因素进行了分析,得出"四水"流域及洞庭湖区工业污染、农业污染(化肥污染、农药污染、水产养殖、畜禽粪便)、生活污染等是导致水环境逐步恶化的主要原因。
Change trend of important parameters of water environment from 1991 to 2009 in the Dongting Lake wetland were analyzed using classical non-parameters statistical test method of Mann-Kendall.Results showed that conductivity,COD,BOD5,total nitrogen,total phosphorus and suspended particles increased significantly from 1991 to 2009;Chroma,E.coli,nitrate nitrogen and ammonium nitrogen increased insignificantly;Dissolved oxygen decreased significantly;pH and transparency decreased insignificantly.So,we could conclude that water quality of the Dongting Lake wetland decreased gradually.Results also indicated that period and frequency of sudden changes of water parameters were different significantly.Sudden changes of other parameters were between two critical lines（p=0.05） except one sudden change of chroma between the two lines（p=0.05 and p=0.01,respectively）.In sudden changes analysis,chroma and suspended particles changed most frequently,total nitrogen and total phosphorus were most steady,and other parameters were in the middle.According to the periods of sudden changes,we could conclude that water quality declined focusing on 1992-1998.In additional,factors that affected water environment of the Dongting Lake were also analyzed in this paper,indicating that pollution from industry,agriculture（chemical fertilizer,pesticide,aquiculture,fences of livestock and poultry） and from human life around ＂Four River＂ basin and Dongting Lake area were main factors that caused water environment to be worse.
出处
《生态环境学报》
CSCD
北大核心
2011年第8期1295-1300,共6页
Ecology and Environmental Sciences
基金
国家林业局公益性行业科研专项(201104065)
湖南省林业科学院青年创新基金项目
