洪湖水质时空特征及污染驱动力分析

Spatio-temporal characteristics of water quality and the pollution driving forces of Honghu Lake

运用主成分分析法和聚类分析法,对2016年洪湖8个常规监测点的8项水质指标进行数据分析,识别洪湖主要污染因子,判别洪湖水质的时空差异性,揭示洪湖水质与污染源的内在联系,分析污染成因。结果表明,2016年洪湖8个监测点均出现超标现象,且入湖断面水质浓度大于出湖断面水质浓度,超标因子主要为COD、TP、TN、氨氮,超标最严重的监测点位为蓝田。丰水期有机污染严重,污染源主要为洪湖内水产围网养殖;枯水期氮磷超标严重,污染主要来源于洪湖流域农业种植及畜禽养殖等;平水期湖体内外源污染都占较大比重。因此,为提高洪湖水质保护水生态环境,应拆除洪湖内围网,并加强对外源污染的控制。

The 8 water quality indices of 8 regular monitoring sites in Honghu Lake were monitored in 2016,and the obtained monitoring data were analyzed by principal component analysis and cluster analysis to identify the main pollution factors,distinguish the spatiotemporal differences,reveal the inner link between water quality and pollution source,and analysis the causes of pollution.Results showed that the water quality of all the 8 monitoring sites exceeded the water quality standard,the pollution in inflowing sites were greater than outlet sites,the main pollution factors were COD,TP,TN and ammonia nitrogen,and the most serious violation site was Lantian.The organic pollutants in wet season were serious,and the main source of pollution was the inner enclosure culture.The nitrogen and phosphorus pollution were more serious in dry season,the pollution mainly comes from the Honghu lake basin livestock and poultry farming and agricultural planting.Both internal and external source accounted for the water pollution in normal season.Therefore,it was necessary to remove the inner seine and strengthen the control of external pollution to improve the water quality of Honghu Lake.