新疆民丰县西部绿洲区地下水水质影响因素分析

Influencing Factors of Groundwater Quality in the Western Oasis Area of Minfeng County,Xinjiang

为掌握新疆民丰县西部绿洲区地下水水化学特征及水质主要影响因素,基于现场井口直接采集的地下水水样,使用现场检测法及实验室测试法相结合得到的24组地下水水样检测数据,运用杜罗夫图研究水化学特征,通过主成分分析法提取水质特征指标,并结合绝对主成分得分-多元线性回归法(APCS-MLR)量化分析地下水水质影响因素。结果表明,研究区地下水整体呈弱碱性微咸水。水中主要阳离子按均值排序依次均为Na^(+)>Ca^(2+)>Mg^(2+)>K^(+),主要阴离子排序分别为SO_(4)^(2-)>Cl^(-)>HCO_(3)^(-)(潜水)与Cl^(-)>SO_(4)^(2-)>HCO_(3)^(-)(承压水),水化学类型以SO_(4)·Cl^(-)Na·Mg型为主;研究区水质特征指标为Na^(+)、Cl^(-)、SO_(4)^(2-)、NO_(3)^(-)、Ca^(2+)、F^(-)、As、溶解性总固体(TDS)和总硬度(TH);地下水水质不仅受到水-岩相互作用与蒸发浓缩作用(自然环境作用),还受农牧业-生活污水(对潜水与承压水的贡献率分别为19.68%与22.14%)的影响。

To grasp the hydrochemical characteristics of groundwater and the main influencing factors of groundwater quality in the western oasis zone of Minfeng County,Xinjiang.Based on the groundwater samples collected directly from the wellhead,24 groups of groundwater sample test data were obtained by combining the field test method and the laboratory test method,the Doruv diagram was used to explore the groundwater chemical characteristics.Principal component analysis was used to select the groundwater quality characteristic indexes,and the influencing factors of groundwater quality were quantitatively analyzed by the absolute principal component score-multiple linear regression(APCS-MLR).Results showed:The groundwater in the study area was weakly alkaline brackish water.According to the average content,the main cations were Na^(+)>Ca^(2+)>Mg^(2+)>K^(+),and the main anions in unconfined groundwater and confined groundwater were SO_(4)^(2-)>Cl^(-)>HCO_(3)^(-) and Cl^(-)>SO_(4)^(2-)>HCO_(3)^(-),and the main hydrochemical types of groundwater were SO_(4)·Cl^(-)Na·Mg type.The characteristic indexes of water quality in the study area were Na^(+),Cl^(-),SO_(4)^(2-),NO_(3)^(-),Ca^(2+),F^(-),As,total dissolved solids(TDS)and total hardness(TH).Groundwater quality was not only affected by water-rock interaction and evaporation concentration(natural environment),but also influenced by agriculture and animal husbandry-domestic wastewater(19.68%and 22.14%contribution to unconfined groundwater and confined groundwater,respectively).