黄河三角洲淡水恢复工程湿地水质监测及其评价研究

Research on Monitoring and Evaluation of Water Quality of Fresh Water Restoration Project Wetlands in the Yellow River Delta

以黄河三角洲引黄沟渠、连河湿地和恢复湿地三种湿地系统2018年实地监测数据为基础,选取化学需氧量(COD)、氨氮(NH3-N)、总磷(TP)、总氮(TN)、铜、锌、铬和铅为评价指标,采用改进内梅罗污染指数法进行水质评价与分析。评价结果显示,仅5月份引黄沟渠水质为Ⅳ类,其余各时期三种湿地系统水质均处于Ⅴ类水质状态,说明用于淡水恢复工程的黄河水也处于重度污染状态,有效削弱污染程度需要对黄河三角洲上游来水进行严格污染管控。三种湿地水质监测结果显示:11月份三种湿地系统中各污染指标均高于5月份和8月份,这是由于11月份各湿地系统水量大量减少所致;而且各湿地系统铜、锌不存在污染风险,而铬、铅存在较大污染风险。因此,建议11月后及时补充黄河水,以有效削弱各湿地系统的污染程度。

Based on the monitoring data of Yin-huang ditch,Lian-he wetland and restoration wetland in the Yellow River Dalta in 2018,the water quality was evaluated by the modified Nemerow index method with chemical oxygen demand(COD),ammonia nitrogen(NH3-N),total phosphorus(TP),total nitrogen(TN),copper,zinc,chromium and plumbum as evaluation indexes.The results showed that the water quality of Yin-huang ditch belonged to ClassⅣin May,and that of all the three wetland systems belonged to ClassⅤin the other periods,indicating that water from the Yellow River was seriously polluted in the freshwater restoration projects,hence,in order to reduce water pollution,it should be necessary to enhance pollution management and control of water from the upstream of the Yellow River Delta.The monitoring results of water quality in the three wetland systems showed that concentrations of all the pollution parameters in November were greater than those in May and August,because the water quantity of the wetland systems markedly decreased.There was no pollution risk of copper and zinc in wetland systems,but chromium and plumbum had higher pollution risk.Hence,it was suggested that timely replenishment of the Yellow River water should effectively weaken the pollution level of wetland systems after November.