南畹河迭撒国控断面水质污染状况评价及污染特征分析

Evaluation of Water Quality Pollution Status and Analysis of Pollution Characteristics in the National Control Section of Nanwan River Diesa

为评价南畹河水质污染状况并分析其变化特征,选取南畹河迭撒国控断面为研究对象,2013—2018年间每月对水质进行监测,并采用单因子评价法、综合污染指数法、内梅罗污染指数法三种方法对水质进行评价。结果表明,按单因子评价法评价6年均值达到《地表水环境质量标准》(GB 3838—2002)Ⅱ类水质要求,水质总体达标,个别年份水质超标;6年平均浓度对应综合污染指数P=0.33,表明南畹河迭撒国控断面综合水质检出值在标准内,个别项目接近或超标;6年平均浓度对应内梅罗综合污染指数P_(N)=0.70,2015、2018年P_(N)>0.7。采用秩相关系数法对水质时间变化规律进行分析,结果表明评价时段内综合水较为平稳。结合降水情况,探讨气候对水质的影响,结果表明,COD_(Mn)、Tp、Cu、Zn与降水有显著相关性。

In order to evaluate the water pollution status of Nanwan River and analyze its changing characteristics,the national control section of Diesa in Nanwan River was selected as the research object.The water quality was monitored monthly from 2013—2018,and three methods were used to evaluate the water quality:single factor evaluation method,comprehensive pollution index method,and Nemero pollution index method.The results show that the 6-year average evaluated by the single factor evaluation method meets the Class II water quality requirements of the Surface Water Environmental Quality Standard(GB 3838—2002),and the overall water quality meets the standard,with some years exceeding the standard;the 6-year average concentration corresponds to the comprehensive pollution index index P=0.33,indicating that the comprehensive water quality detection value of the national control section of the Nanwan River is within the standard,and some projects are close to or exceed the standard;the 6-year average concentration corresponds to the Nemero comprehensive pollution index P_(N)=0.70,2015 and 2018P_(N)>0.7.The rank correlation coeffi cient method was used to analyze the temporal variation pattern of water quality,and the results showed that the comprehensive water quality was relatively stable during the evaluation period.Based on the precipitation situation,this study explores the impact of climate on water quality.The results show that there is a signifi cant correlation between COD_(Mn),Tp,Cu,Zn and precipitation.