基于多元分析的北京市通州区主要河流水质时空变化

Multiple analyses on time-temporal change of water quality in major rivers of Tongzhou,Beijing

为评估北京市通州区域河流水质时空变化状况,选取该区域主要河流的8个监测断面于2012—2020年间的水质监测数据进行分析.水质监测指标包括溶解氧(DO)、化学需氧量(COD_(Cr))、氨氮(NH_(4)^(+)-N)、总磷(TP)、生化需氧量(BOD_(5))、高锰酸盐指数(COD_(Mn))、粪大肠菌群、硫化物和挥发酚等9项.借助单因子水质标识指数法、箱线图法及主成分分析法,研究了通州区河水水质时空特征和污染来源.结果表明,通州河流枯水期的水质比丰水期差,下游的水质比上游差,主要污染物有高锰酸盐指数、粪大肠菌群、氨氮、总磷等.这些污染物的类型主要与这些河流所承担的城市排污任务有关.同时从时间上分析,自2016年起通州河流总体水质得到大幅度改善,并持续好转,由此可见近几年通州河流治理效果较好.建议相关管理部门加大对河流、河道、渠道等水系周边环境的修复和建设力度,加强智慧河湖管理平台建设,实现精细化治水、智能化管河.最后,还应拓展宣传渠道,提高市民保护意识,自觉巩固和维护水环境的治理成果.

To evaluate the rivers of water quality in Tongzhou area, the water quality data of eight monitoring section in Tongzhou’s main rivers during 2012—2020 were selected for analysis. The water quality data include nine indicators like dissolved oxygen(DO), chemical oxygen demand(COD_(Cr)), ammonia nitrogen(NH_(4)^(+)-N), total phosphorus(TP), biochemical oxygen demand(BOD_(5)),permanganate index(COD_(Mn)), fecal coliforms, sulfides, volatile phenols and so on. The spatialtemporal features and pollution sources of river’s water quality were analyzed via methods of single factor index, boxplot and principal component analysis. The results demonstrated that the water quality of drought period was worse than that of high flow period toward the rivers, and the water quality of downstream was worse than that of upstream, which could be concluded from the excess of CODMn, fecal coliforms, NH_(4)^(+)-N, TP and others. The main reason of pollution was attribute to municipal sewage discharge. Fortunately, the water quality of most Tongzhou ’s rivers has been greatly improved since 2016, which could be attribute to the good governance in recent years. It was suggested that the relevant administrative departments should strengthen the remediation and protection of the surrounding environment of rivers and lakes. And the smart river and lake management platform should also be established to realize refine control and intelligent management of rivers. Finally, the publicity channels should also be expanded and the awareness of public protection should further be improved to maintain the achievements of water environment.