榆林市黄河水系主要河流水质现状评价与分析

目的研究榆林市境内黄河水系主要河流水质现状,对其进行评价和分析,为榆林市水环境治理和污染物控制提供参考依据。方法以2013-2015年榆林市境内黄河水系4条主要干支流段的12个监测断面数据为研究基础,采用模糊综合评价法和水质标识指数法对其进行水质现状评价,并分析其污染成因。结果研究结果表明,黄河榆林段一级支流窟野河和无定河达到相应水质功能标准要求,黄河榆林段二级支流榆溪河水质不达标,为Ⅳ类水。从2013-2015年年际变化来看,榆溪河水质表现出逐渐恶化的趋向;从空间特征来看,榆溪河上游水质达标,中下游水质劣于Ⅲ类水。榆溪河的特征污染指标为化学需氧量(COD)、生化需氧量(BOD)、氨氮(NH3-N)和总磷(TP),来源为城市生产生活污水和农业退水。结论榆林市境内黄河水系干流段及2条主要的一级支流水质良好,二级支流榆溪河存在轻度污染,其主要污染指标为COD、BOD、NH3-N和TP。

Evaluation and analysis of the water quality of the main rivers in the drainage system of the Yellow River within the territory of Yulin City

Purposes—To study the water quality of the main rivers in the drainage system of the Yellow River within the territory of Yulin City,Shaanxi,China and to provide reference basis for wa-ter environment control and pollutant control in Yulin City.Methods—With the data from 12 monito-ring cross sections of four main rivers in the drainage system of the Yellow River within the territory of Yulin City from 2013 to 2015 as the research foundation,the fuzzy comprehensive evaluation meth-od and the water quality index method were used to evaluate water quality and analyze the pollution causes.Results—The results showed that the water in the Kuye River and Wuding River,primary tributaries of the Yellow River within Yulin reaches of the Yellow River,was up to the corresponding water quality standard,the water in the Yuxi River,secondary tributary of the Yellow River within Yulin reaches of the Yellow River belonged to class Ⅳ water,not up to standard.In the terms of the changes during the period from 2013 to 2015,the water quality of the Yuxi River showed a tendency to gradual deterioration.From the point of space characteristics,the water quality in the upstream of the Yuxi River was up to standard,the water quality in the middle and lower reaches of the Yellow River was worse,belonging to the class Ⅲ water.The characteristic pollution indicators of the Yuxi River were COD,BOD,NH3-N and TP,which sources from agricultural waste water and the polluted industrial waste water and domestic sewage which are drained from urban area.Conclusion—The wa-ter in the main stream of the Yellow River within the territory of Yulin City and its two main primary tributaries was of good quality.The Yuxi River,secondary tributary of the Yellow River,was slight-ly polluted,and its main pollution indicators were COD,BOD,NH3-N and TP.