悖牛川上中游区地下水水化学特征及其成因分析

Analysis of Groundwater Hydrochemical Characteristics and Its Formation Mechanism in the Upper-middle Reaches of Beiniuchuan River

地下水化学特征及其成因分析是地下水资源评价与管理的重要组成部分。本文在对悖牛川上、中游区详细的水文地质调查基础上,运用描述性统计分析、相关性分析、离子比值法、同位素等方法对研究区地下水化学特征及成因进行了分析。研究结果表明:区域地下水总溶解性固体(TDS)含量在170~1034 mg/L之间,随着TDS含量的升高,水化学类型由HCO_3-Ca(·Mg)型转变为HCO_3·SO_4-Ca·Na型、Cl-Na型。溶滤作用是控制区域地下水化学组分形成的主要作用,地下水化学组分来源于碳酸盐、铝硅酸盐和蒸发岩的溶解。此外,阳离子交替吸附作用、脱硫酸作用和混合作用也对区内水化学组分形成存在一定影响。煤炭开采使赋存于煤层以上的地下水水化学演化趋于一致,地下水TDS含量升高,水质趋于恶化。

Analysis of groundwater hydrochemical characteristics and its formation mechanism is an important part of groundwater resources assessment and management.Based on the thorough hydrogeological investigation in upper-middle Reaches of Beiniuchuan River,the groundwater hydrochemical characteristics and its formation mechanism were analyzed in this present paper,by using the methods of descriptive statistical analysis,correlation analysis,ion ratio and isotopes etc.The results show these as follows.①The total dissolved solids(TDS)of the regional groundwater is 170~1 034 mg/L.②With the increase of TDS,the hydrochemical type changes from HCO 3-Ca(·Mg)to HCO 3·SO 4-Ca·Na type and Cl-Na type.③The formation of groundwater chemical components is mainly controlled by leaching,and the chemical composition of groundwater originated from dissolution of carbonate,aluminosilicate and evaporate,besides,the cation exchange and adsorption,sulfate reduction and mixing also have influences on the formation of water chemical components to some extent in the study area.It is concluded that coal mining makes the chemical evolution of groundwater above the coal seam tend to be similar,TDS increases and water quality deteriorates.