嘉陵江南充段水质评价及其污染源解析

Analysis of Water Quality Evaluation and Pollution Sources in Nanchong Section of Jialing River

以2017—2019年南充市嘉陵江一级支流25个监测断面的年均值监测数据为研究对象,运用多种评价方法对水环境质量进行分析,并采用GIS和多元统计法分析水质变化特征及潜在污染物来源。结果表明,综合水质标识指数法最适合南充市嘉陵江一级支流河长考核制。嘉陵江南充段一级支流水质逐年改善,污染程度从高到低依次为蓬安县>高坪区>南充市>嘉陵区>阆中市>顺庆区>南部县>仪陇县;该地区主要污染物指标为化学需氧量(CODCr)、五日生化需氧量(BOD5)、总磷(TP)、氨氮(NH3-N)。主要受有机污染、富营养化污染和粪便污染的影响,工业废水、农业径流、生活污水以及畜牧污染物的排放是流域主要污染源。

Based on the 2017-2019 monitoring data of Nanchong Jialing River first level 25 tributaries monitoring section as the research object,the water environment quality was analyzed by various evaluation methods,and the water quality change characteristics and potential pollutant sources were analyzed by GIS and multivariate statistical methods.The results showed that comprehensive water quality identification index method was the most suitable for the river chief examination system of the first grade tributary of Jialing River in Nanchong City.The water quality of the first level tributaries in Nanchong section of Jialing River improved year by year.The pollution degree ranked as follows Peng’an County>Gaoping District>Nanchong City>Jialing District>Langzhong City>Shunqing District>Nanbu County>Yilong County.The main pollutant indexes in this area were COD Cr,BOD 5,TP,NH 3-N.It was mainly affected by organic pollution,eutrophication pollution and fecal pollution,and the four major pollution sources in the basin were industrial wastewater,agricultural runoff,domestic sewage and livestock pollutant discharge.