苏州湖泊水源地水质时空变异特征

The Temporal and Spatial Variations of Water Quality in Lake Water Sources of Suzhou

基于多元统计方法分析了苏州市太湖、阳澄湖、尚湖和傀儡湖等9个湖泊水源地2006-2017年12年间17个水质指标的时空变异特征,结果表明:9个水源地水质状况总体处于轻度污染状态;富营养程度年际呈上升趋势,年内呈季节变化特征,汛期(多为轻度富营养)高于非汛期(多为中营养);水质聚类和判别分析表明,9个水源地在汛期(7-10月)和非汛期(1-6月和11、12月)水质存在明显差异,且从空间尺度上可分为昆山、常熟及太湖不同区域;基于主成分分析的3组水源地污染源解析表明,昆山区域以富营养污染为主,常熟区域以有机污染及农业面源污染为主,太湖区域以内外源复合的氮素污染为主。分析结果可为湖泊水源地的水质保护及污染控制提供参考。

Multivariate statistical methods are used to analyze the temporal and spatial variations of 14 water quality indicators in 9 lake water sources of Suzhou from 2006 to 2017.The Nemero index method is used to calculate the comprehensive water quality status of 9 water sources over 12 years.Results show that 9 water sources are generally considered as mild pollution.The eutrophication status is on an upward trend in 12 years.and is characterized by seasonal variations during the year.The flood season(mostly mild eutrophication)is higher than the non-flood season(mostly medium nutrition).Cluster analysis(CA)and discriminant analysis(DA)results show that the water quality of 9 water sources is significantly different between flood season(July-October)and non-flood season(January-June,November,December).The water quality can be divided into Kunshan Area,Tai Lake Area and Changshu Area at spatial scale.Principal component analysis(PCA)results show that the water quality of Kunshan Area is mainly polluted by eutrophic pollution.Tai Lake Area is mainly affected by organic pollution and agricultural non-point source pollution.Changshu area is mainly polluted by nitrogen pollution.The results serve as a guide to the protection of water quality and pollution control of lake water sources.