什邡市城市规划区地下水化学特征及演化模拟

基于什邡市城市规划区的水文地质条件,采用Aqua Chem软件分析研究区地下水主要组分的物质来源和水岩相互作用过程、借助PHREEQC软件对其进行反向水文地球化学模拟。分析表明:研究区地下水属于低矿化度淡水,地下水化学类型主要为HCO_3·SO_4-Ca型、HCO_3·SO_4-Ca·Mg型,局部为HCO_3·SO_4·Cl-Ca型,主要阳离子空间分布特征显示,自西北向东南离子浓度不断增加,与地下水流向基本一致; PHREEQC反向水文地球化学模拟结果显示在水流模拟路径上主要发生了高岭石、钾长石溶解,伊利石的迁出,阳离子交替吸附作用为Na~+、Ca~(2+)的互换;离子相关性分析显示随着地下水流动路径的增加,溶解性固体总量(TDS)将会随着矿物的不断溶解,逐渐增大。地下水水中各离子浓度大小与相关矿物溶解具有关联性。

Groundwater chemical characteristics and evolution simulation in urban planning area of Shifang City

Based on the hydrogeological conditions of Shifang City urban planning area, AquaChem software was used to analyze the material source of the main groundwater components and interaction processin between water and rock, the reverse hydrogeochemical simulation was carried out by PHREEQC software. The analysis shows that: The groundwater in the study area belongs to low salinity freshwater. The chemical types of groundwater are mainly HCO3·SO4-Ca type, HCO3·SO4-Ca·Mg type, partly as HCO3·SO4·Cl-Ca type; The spatial distribution characteristics of the main cations show that the ion concentration increases from northwest to southeast, which is basically consistent with the direction of groundwater flow. PHREEQC reverse hydrogeochemical simulation results show that kaolinite and potassium feldspar dissolve in the flow simulation path, illite migrates out, and cation alternate adsorption is the exchange of Na+ and Ca2+. The ion correlation analysis shows that TDS will increase with the continues dissolve of minerals with the increase of groundwater flow path. The concentration of ions in groundwater is related to the dissolution of related minerals.