乌鲁木齐河地表水化学组成及时空分布特征

Composition and Temporal-Spatial Distribution of Surface Water in Urumqi River

乌鲁木齐河作为乌鲁木齐市的主要水源地,在生态保护和城市供水中均具有重要的战略意义。为了研究乌鲁木齐河水化学特征及水环境质量,于2016年4—10月逐月对乌鲁木齐河6个采样断面进行地表水样采集,获取水样41个,对主要离子(K^+、Na^+、Ca^(2+)、Mg^(2+)、Cl^-、HCO_3^-、SO_4^(2-))浓度及pH、DO、TDS、CODMn、TN、TP、NH3-N进行监测分析,探讨了水化学组成的时空差异及影响因素,研究了乌鲁木齐河的水环境质量状况。结果显示,乌鲁木齐河水域年离子总量平均值为213.27 mg/L,属弱矿化度水,年离子总量在空间上表现出沿主河道由南向北逐步增加的趋势。主要阴离子为HCO_3^-和SO_4^(2-),主要阳离子为Ca^(2+),水质类型为Ca^(2+)-HCO_3^--SO_4^(2-)型。2016年河水年内不同时期TDS平均浓度排序为:9月>10月>4月>5月>6月>8月>7月。对水化学离子含量基于时间序列分析,结果显示除Ca^(2+)、HCO_3^-外,其他离子含量在各月份间均存在显著差异。SO_4^(2-)浓度在年内变化最为明显,呈现先减少后增加的趋势。对主要离子含量基于空间序列进行分析,结果显示,仅Na+含量存在显著差异。现阶段乌鲁木齐河的水环境质量为轻度污染。

The Urumqi River is the main water source in Urumqi and has important strategic significance in ecological protection and urban water supply. In order to study the chemical characteristics and water quality of Urumqi River,41 samples of water samples were collected from 6 sampling sections of Urumqi River since April to October in 2016. The concentration of main ions（ K^＋,Na^＋,Ca^2＋,Mg^2＋,Cl^-,HCO3^- ,SO4^2-）,p H,DO,TDS,CODMn,TN,TP and NH_3-N were monitored and analyzed. The temporal and spatial differences,and influencing factors of water chemistry were discussed,the water environment quality situation was studied. The results show that the average annual ion concentration in the Urumqi River is 213. 27 mg/L,which is a weak mineralization degree. The annual total ion has a tendency to gradually increase from south to north along the main river channel. The main anions are HCO3^- and SO4^2-,the main cation is Ca^2＋,and the water quality type is Ca^2＋-HCO3^- -SO4^2-type. The average concentration of TDS in different periods of the river year in 2016 is： September〉 October 〉April〉 May 〉June 〉August 〉July. The results showed that there were significant differences in the contents of other ions except Ca^2＋and HCO3^- in the time series. Concentration of SO4^2-in the year present the most obvious change,showing the decrease at first and then increase trend. The main ion contents were analyzed based on the spatial sequence,and the results showed that only Na＋content was significantly different. The water quality of the Urumqi River is mild polluted at present.