黄石市磁湖水质时空分布及污染源解析

Temporal and spatial distribution of water quality and source apportionment in Cihu Lake,Huangshi City

为解析黄石磁湖污染来源和水质时空分布,以磁湖2015—2019年水质监测数据为基础进行污染因子主成分分析(PCA),通过绝对主成分-多元线性回归(APCS-MLR)受体模型计算污染源贡献率,采用反距离权重插值法(IDW)分析水质时空分布规律。结果表明:影响磁湖水质的第1、第2、第3主成分分别是城市面源、城镇生活污染源及气象因子;第1主成分对BOD_(5)、COD_(Cr)、COD_(Mn)、NH_(3)^(-)N、TN、TP的贡献率最大,分别为88%、76%、67%、55%、46%、67%,第2主成分对BOD_(5)、NH_(3)^(-)N的贡献率较大,分别为39%、32%。磁湖主要污染来源为城市面源及城镇生活污染源,受历史上工矿企业生产造成的底泥淤积和上游区域城镇生活污水排放的影响,磁湖下陆港入湖口(1#点位)处的污染最严重。

In order to analyze the pollution sources and the spatial and temporal distribution of water quality in Cihu Lake,the principal component analysis(PCA)of pollution factors was conducted based on the water quality monitoring data of Cihu Lake from 2015 to 2019,and the contribution rate of pollution sources were calculated by absolute principal component score-multiple linear regression(APCS-MLR)receptor model,and the inverse distance weight interpolation(IDW)method was used to analyze the spatial and temporal distribution pattern of water quality.The results showed that the 1st,2nd and 3rd principal components affecting the water quality of Cihu Lake were urban non-point sources,urban domestic pollution sources and meteorological factors,respectively;the contribution of the 1st principal component to BOD_(5)(88%),COD_(Cr)(76%),COD_(Mn)(67%),NH_(3)^(-)N(55%),TN(46%)and TP(67%)was the largest,and the contribution of the 2nd principal component to BOD_(5)(39%),NH_(3)^(-)N(32%)was larger.Overall,the main pollution sources of Cihu Lake were urban non-point sources and urban domestic pollution sources.From the spatial and temporal distribution map of the water quality,it could be seen that the most serious pollution was at the inlet of Xialu Port(point 1#),which was mainly affected by the siltation of bottom mud formed by the production of historically industrial and mining enterprises and urban domestic sewage in the upstream area.