嘉陵江一级支流县域河流水质现状综合分析与评价——以南充市蓬安县为例

The Comprehensive Analysis and Evaluation of the Water Quality Status of the First Tributaries of Jialing River at County Level——A Case Study of Peng’an County,Nanchong City

以南充市蓬安县为例,采用了单因子评价法、主要污染物水质标识指数法和主成分分析法统计分析了2017~2019年嘉陵江一级支流蓬安数据,综合分析嘉陵江一级支流县域河流水污染特征及水质评价。结果表明:(1)蓬安县域内嘉陵江一级支流水环境有机污染较为严重,污染物主要源于生活污水、工业污水、农业面源污染排放,高风险因子为COD_(Cr)和TP。(2)水质受水期影响大,变化特征为:枯水期>丰水期>平水期;上半年水质优于下半年,1~3月水质最差。(3)蓬安县域内嘉陵江支流年均值评价水质逐年改善,达标率逐年增加,污染程度依次为清溪河>河舒河>大泥溪>长塘河>金溪河。就蓬安县的水质评价结果进行问题剖析,为嘉陵江流域污染防治管理提供科学依据。

Taking Peng’an county in Nanchong city as an example,this paper used the single-factor evaluation method,the water quality identification index method of major pollutants and the principal component analysis method to statistically analyze the data of Peng’an,the first tributary of Jialing river from 2017 to 2019,and comprehensively analyzed the water pollution characteristics and water quality evaluation of the first tributary of Jialing river.The results showed that:(1)The environmental organic pollution of the primary branch of the Jialing river in Peng’an county was relatively serious,and the pollutants were mainly from the discharge of domestic sewage,industrial sewage and agricultural non-point source pollution,and the high risk factors were COD_(Cr)and TP.(2)The water quality was greatly affected by the water period,and the variation characteristics were as follows:dry period>wet period>normal period;The water quality in the first half of the year was better than that in the second half of the year,and the water quality in January-March was the worst.(3)The annual mean value evaluation of the water quality of the tributaries of the Jialing river in Peng’an county improved year by year,the compliance rate increased year by year,and the pollution degree was in the order of Qingxi river>Heshu river>Dani river>Changtang river>Jinxi river.This paper analyzed the results of water quality evaluation in Pengan County to provide scientific basis for pollution prevention and control management in Jialing river.