新疆昌吉州东部平原区地下水水文地球化学演化分析

为探究新疆昌吉州东部平原区地下水水质演化过程，采用数理统计、Piper三线图、Gibbs图和离子比法对昌吉州东部平原区2016年63组地下水水质取样点及54组2012—2015年地下水水质监测数据进行分析。结果表明：昌吉州东部平原区2012年地下水阳离子平均含量总体为Ca²⁺>K⁺+Na⁺>Mg²⁺，阴离子平均含量总体为HCO^3->SO₄^2->Cl^-；从2013年开始，SO₄^2-逐渐增大，Ca²⁺逐渐减小；到2016年阳离子平均含量总体为Ca²⁺>K⁺+Na⁺>Mg²⁺，阴离子平均含量总体为HCO₃^->SO₄^2->Cl^-。水化学类型由2012年HCO₃—Ca·Mg（Ca·Na、Ca·Na·Mg）型向2016年HCO₃·SO₄—Ca·Na·Mg（Ca·Mg、Ca·Na）演化，这主要与含水介质的风化作用和蒸发浓缩作用有关，而蒸发浓缩作用更加体现在承压水区的上部潜水中。地下水中Na⁺、K⁺、Cl^-主要来自岩盐的溶解；Ca²⁺、Mg²⁺主要来自蒸发岩溶解；SO₄^2-主要来自石膏（CaSO₄·2H₂O）和芒硝（Na₂SO₄·10H₂O）的溶解。Cl^-、SO₄^2-除来自岩盐的溶解外，还受到人类活动的影响。

Hydrogeochemical Evolution Process of Groundwater in the Eastern Plains in Changji Hui Autonomous Prefecture,Xinjiang

In this paper, the test data of 63 groundwater samples in 2016 and 54 water quality monitoring data from 2012 to 2015 in the eastern plains in Changji Hui Autonomous Prefecture, Xinjiang were analyzed by the mathematical statistics, Piper diagrams, Gibbs figures, ion ratios, etc. The purposes of this study was to explore the evolution process of groundwater in the study area. The results showed that the average cationic concentrations of groundwater in the study area in 2012 were in an order of Ca²⁺ > K⁺+Na⁺ > Mg²⁺, and the average anionic concentrations were in an order of HCO₃^- > SO₄^2- > Cl^-. After 2013, the concentration of SO₄^2- was gradually increased but that of Ca²⁺ was gradually decreased. By 2016, the average cationic concentrations of groundwater were in an order of Ca²⁺ > K⁺+Na⁺ > Mg²⁺, and the average anionic concentrations were in an order of HCO₃^- > SO₄^2- > Cl^-. The hydrochemical type evolved from HCO₃—Ca·Mg (Ca·Na, Ca·Na·Mg) in 2012 to HCO₃·SO₄—Ca·Na·Mg (Ca·Mg, Ca·Na) in 2016, which was mainly related to the evaporation and rock weathering of aquifer medium, and the evaporation was reflected more in unconfined groundwater. Na⁺, K⁺ and Cl^- in groundwater came mainly from the dissolution of rock salt; SO₄^2- came mainly from the dissolution of gypsum (CaSO₄·2H₂O) and mirabilite (Na₂SO₄·10H₂O). In addition to the dissolution of rock salt, Cl^- and SO₄^2- are also affected by human activities.