新疆和田东部平原区地下水化学特征及演化规律

Hydrochemical characteristics and evolution of groundwater in the eastern plain of Hotian Prefecture,Xinjiang

以2018年新疆和田东部平原区116组地下水水质检测数据为基础,综合运用因子分析、Piper三线图、Gibbs模型、离子比值法和水文地球化学模拟等方法对其水化学特征及演化规律进行分析.结果表明:研究区地下水中Na^(+)和Mg^(2+)为主要阳离子,Cl^(-)和SO_(4)^(2-)为主要阴离子,地下水类型为SO_(4)·ClCa·Mg型高硬度高咸水;因子分析表明该区地下水水化学组分受岩石溶滤作用和蒸发浓缩作用控制;水中离子主要来源于蒸发盐岩的溶解,其次为碳酸盐岩和硅酸盐岩的溶解.单一结构潜水主要受蒸发浓缩作用、岩石溶滤作用和人类活动等因素影响,承压水受阳离子交换作用影响.水文地球化学模拟结果表明:沿地下水流向,水中离子总量累积,岩盐、白云石和石膏发生溶解,方解石发生沉淀.

Based on the groundwater quality test data of 116 groups in the eastern plains area of Hotian Prefecture,Xinjiang in 2018,the chemical characteristics and evolution law of groundwater were comprehensively analyzed by means of factor analysis,Piper trigraph,Gibbs model,ion ratio and hydrogeochemical simulation.The results showed that:Na^(+) and Mg^(2+) were the main cations the groundwater.Cl^(-) and SO_(4)^(2-) were the main anions in the groundwater,and the groundwater hydrochemistry type was SO_(4)·Cl—Ca·Mg type high hardness and salt water.Factor analysis showed that the chemical composition of groundwater was controlled by dissolution of rocks and evaporation concentration.The groundwater ions were mainly derived from the dissolution of evaporates rocks,followed by the dissolution of evaporates and carbonates.Single structure unconfined groundwater was mainly affected by evaporation and concentration,dissolution of rocks and human activities while the confined groundwater was affected by cation exchange.Along the groundwater flow direction,the hydrogeochemical simulation results indicate that the total amount of ions in the groundwater accumulated.Halite,dolomite,and gypsum were dissolved,and calcite was precipitated.