西部生态环境脆弱区地下水水化学特征分析

Hydrochemical Characteristics Analysis of Groundwater in the Western Eco-Enviroment Fragility Area

为了评价榆神矿区和神府矿区地下水水化学特征与演化规律,在研究区采集了53组地下水样品并进行检测,通过计算阴阳离子贡献率、不同离子的相关系数、Na^+与Cl^-毫克当量比值,绘制不同含水层地下水Piper三线图、Gibbs分布图,分析了地下水离子特征和水化学特征。分析发现,研究区地下水均为弱碱性水;受蒸发作用影响,溶解度较小的Ca^(2+)相继析出,是地下水离子贡献率最高的阳离子;马兰黄土地下水的TDS含量最低,冲洪积含水层地下水TDS含量最高;总硬度从风沙滩地向黄土区逐渐增高;Ca^(2+)、SO_4^(2-)与TDS呈极高相关性;地下水化学特征主要受水-岩作用控制,风沙滩地区地下水以HCO_3类水为主,黄土梁峁区为HCO_3·SO_4类水。

In order to evaluate thehydrochemical characteristics and evolution of groundwater in Yushen mining area and Shenfu mining area,53 samples of groundwater of the researched area were collected and tested.It calculated the contribution rates of cations and anions,correlation coefficient matrix method,piper trilinear diagram,Gibbs distribution graph and milligram equivalent ration with Na^+ and Cl^- by mathematical statistics.It analyzed the characteristics of groundwater ion and hydrochemical characteristics and drew the isogram of groundwater hardness in the area and zoning map of hydrochemical type.The results show that the groundwater in the area is weak alkaline water.The less solubility of Ca^2+ is precipitated out,which is affected by evaporation,is the highest contribution rate.The groundwater TDS content of Malan loess is the lowest and the groundwater TDS in the blunt pluvial aquifer is the highest.The total hardness increases gradually from the blownsand region to the loess area.Ca^2+ and SO4^2- are highly correlation with TDS.Groundwater hydrochemical characteristics are mainly controlled by water-rock interaction,the groundwater is dominated by HCO3 water in the blown-sand region and it is dominated by HCO3·SO4 water in loess ridge-hilly area.