基于主成成分分析的水质考核排名研究——以涪江四川国省考断面为例

Water Quality Assessment and Ranking Study Based on Main Component Analysis——Taking Sichuan Guokao Section of Fujiang River as an Example

为探究涪江流域6种水污染物高锰酸盐指数(I_(Mn))、化学需氧量(COD)、生化需氧量(BOD_(5))、氨氮(NH_(3)-N)、总磷(TP)和挥发酚(Ar-OH)间相互关系及影响水质考核排名的关键指标,使用2022年涪江流域34国省考断的6种主要水污染物浓度监测数据,结合Pearson相关性分析和主成分分析,对34个断面四川省水质排名状况和影响四川水质考核排名的关键指标进行了综合评价与分析。结果表明,以Ar-OH为主的第2主成分方差贡献率(18.374%)远低于以I_(Mn)、COD、BOD_(5)、NH_(3)-N、和TP为主的第1主成分方差贡献率(64.005%),水质综合指数考核排名与主成分分析结果前4位和后3位完全一致,其中后13位的断面排序基本一致,其余不完全一致。因此,经主成分综合评价指数排名可快速找出排名重点关注断面,再通过第1主成分排序精准锁定影响水质考核排名的关键指标,为提升水质考核排名以及开展水污染防治提供理论依据。

To explore the interrelationships and key indicators affecting the water quality assessment ranking among six water pollutants in the Fujiang River Basin,including permanganate index(IMn),chemical oxygen demand(COD),biochemical oxygen demand(BOD_(5)),ammonia nitrogen(NH_(3)-N),total phosphorus(TP),and volatile phenols(Ar-OH),the monitoring data of six major water pollutants concentrations from 34 Guosheng sections in the Fujiang River Basin in 2022 was used to comprehensively evaluate and analyze water quality ranking in Sichuan and the key indicators affecting the Sichuan water quality assessment,in combination with Pearson correlation analysis and principal component analysis.The results showed that the variance contribution rate(18.374%)of the second principal component,mainly composed of Ar-OH,was much less than that(64.005%)of the first principal component,mainly composed of IMn,COD,BOD_(5),NH_(3)-N,and TP.The results of the principal component analysis were completely consistent with the top 4 and bottom 3 positions of the water quality comprehensive index assessment ranking,with the sorting of the last 13 sections being basically consistent,and the others being partially consistent.Therefore,the ranking of the principal component comprehensive evaluation index can quickly identify the key focus sections of the ranking,and then accurately identify the key indicators that affect the ranking of water quality assessment through the first principal component ranking,providing a theoretical basis for improving the ranking of water quality assessment and carrying out water pollution prevention and control.