和静县平原区地下水质量评价与影响因素分析

Evaluation of groundwater quality and analysis of influencing factors in plain area of Hejing county

采用单因子评价法对和静县平原区地下水进行质量评价,采用内罗梅污染指数法对该区地下水污染现状进行评价,采用Piper三线图分析了地下水化学类型,结果表明:研究区地下水质量整体较好,潜水以Ⅱ类水为主,浅层承压水以Ⅱ类、Ⅲ类水为主,深层承压水以Ⅲ类水为主。潜水、浅层承压水、深层承压水的质量超标率分别为25%、19.05%和33.33%.从地下水受污程度来看,浅层承压水>潜水>深层承压水。该区潜水主要为HCO_(3)^(-)·SO_(4)_^(2-)-Ca^(2+)·Mg^(2+)型,浅层承压水为HCO_(3)^(-)·SO_(4)^(2-)-Mg^(2+)·Ca^(2+)·Na^(+)型,深层承压水为HCO_(3)^(-)·SO_(4)_^(2-)·Cl^(-)-Ca^(2+)·Na^(+)·Mg^(2+)型。从山前到细土平原,水化学类型逐渐由HCO_(3)^(-)·SO_(4)_^(2-)-Ca^(2+)·Mg^(2+)型过渡到HCO_(3)^(-)·SO_(4)_^(2-)·Cl^(-)-Ca^(2+)·Na^(+)·Mg^(2+)型。影响研究区水质劣化的主要因素有气候因素、地层岩性、地下水超采、工农业生产和生活排放。

The single factor evaluation method and the Nairome Pollution Indexmethod are used to evaluate the groundwater quality and the present situation of groundwater pollution in plain area of Hejing County.The results showed that the groundwater quality is good in study area.The phreatic water is Class II mainly,the shallow confined water is Class II and Class III,and the deep confined water is Class III.The over-standard rates of phreatic water,shallow confined water and deep confined water are 25%,19.05%and 33.33%respectively.From the polltution degree of ground water,shallow confinedwater>phreatic water>deep confined water.The phreatic water in this area is HCO_(3)^(-)·SO_(4)_^(2-)-Ca^(2+)·Mg^(2+)type,the shallow confined water is HCO_(3)^(-)·SO_(4)^(2-)-Mg^(2+)·Ca^(2+)·Na^(+)type,and the deep confined water is HCO_(3)^(-)·SO_(4)_^(2-)·Cl^(-)-Ca^(2+)·Na^(+)·Mg^(2+)type by Piper three-line diagram.The hydro chemical types changed from HCO_(3)^(-)·SO_(4)_^(2-)-Ca^(2+)·Mg^(2+)to HCO_(3)^(-)·SO_(4)_^(2-)·Cl^(-)-Ca^(2+)·Na^(+)·Mg^(2+)type gradually from piedmont plain to fine soil plain.The main factors causing groundwater pollution are formation lithology,climate factors,groundwater overexploitation,industrial and agricultural production and domestic discharge.