青弋江流域水质评价及时空变化特征分析

Water Quality Evaluation and Spatiotemporal Variation Characteristics of Qingyi River Basin

采用单因子评价法、模糊综合评价法和主成分分析法对青弋江流域7个监测断面2017—2019年6项水质指标的监测数据进行分析,识别了流域的主要水质指标,得出青弋江流域的综合水质状况和水质时空变化趋势。结果表明:青弋江流域整体水质为优,主要水质指标为NH_(3)-N和TP;下游因工业污染源较多,水质最差,上游主要污染源为林地腐殖质等带来的N、P污染,随着水体自净中游水质优于上游;汛期由于雨水冲刷带来的农业面源污染加重,水质劣于其他月份,随着对流域污染源排放管控的加强,流域水质随时间推移呈优化趋势。

The single factor evaluation method,fuzzy comprehensive evaluation method and principal component analysis method were used to analyze the monitoring data of six water quality indicators of seven sections in Qingyi River Basin from 2017 to 2019.The main water quality indexes of the basin were identified.The comprehensive water quality and the spatiotemporal trends of water quality were obtained.The results showed that the overall water quality of Qingyi River Basin was excellent,and the main water quality indicators were NH_(3)-N and TP;the downstream water quality was the worst due to the large number of industrial pollution sources,and the main pollution source in the upstream was N and P pollution caused by forest humus.With the self purification of water body,the water quality in the middle reaches was better than that in the upper reaches;the water quality in flood season was worse than that in other months due to the agricultural non-point source pollution caused by rainwater,and the water quality of the basin tends to be optimized over time with strengthening the management of pollution discharge.