关中盆地浅层地下水地球化学的形成演化机制  

Geochemical evolution mechanisms of shallow Groundwater in Guanzhong basin,China

作　　者：孙一博[1,2,3] 王文科[1,2,3] 段磊[1,2,3] 张春潮[1,2,3] 王宇航[1,2,3] 

机构地区：[1]旱区地下水文与生态效应教育部重点实验室,陕西西安710054 [2]陕西省地下水与生态环境工程中心,陕西西安710054 [3]长安大学环境科学与工程学院,陕西西安710054

出　　处：《水文地质工程地质》2014年第3期29-35,共7页Hydrogeology & Engineering Geology

基　　金：中国地质调查局地质大调查计划项目;国家自然科学基金(41102150)

摘　　要：在对关中盆地浅层地下水169个水化学数据分析的基础上,运用图解法、数理统计法及Phreeqc模拟等方法对关中盆地浅层地下水水文地球化学形成演化机制进行系统研究,取得了一些新的认识。按含水介质及地下水循环特征,将浅层地下水系统大致划分为强烈径流区、缓慢径流区、排泄区。不同水动力分区中,地下水化学类型具有一定的分带性,从强烈径流区、缓慢径流区至排泄区,地下水的化学类型由HCO3-Ca·Mg型经过HCO3-Ca·Mg·Na型逐步演化为SO4·Cl-Na型。地下水强烈径流区,地下水化学组分的形成主要以碳酸盐、硅酸盐等矿物岩石风化作用为主,缓慢径流区以多种作用为主,排泄区由Na-Ca阳离子交换及蒸发浓缩作用控制。Based on analysing 169 hydro-chemical data of shallow groundwater from Guanzhong basin,China, the graphical method,mathematical statistics and phreeqc simulation method were applied to study the chemical characteristics of groundwater and evolutional mechanism. According to the aquifer medium and characteristics of groundwater circulation,the study area can be divided into three hydro-geochemical zones, namely,the strong runoff zone,the slow runoff zone and the discharge zone. In different hydrodynamic zones, groundwater chemical type has certain zonality. The hydro-chemical type of the groundwater in the strong runoff zone and the slow runoff zone runs to the discharge zone from HCO3-Ca·Mg to HCO3- Ca·Mg·Na and further to SO4· Cl-Na. In the strong runoff zone,the formation of the chemical composition of groundwater were controlled by silicate minerals weathering,carbonate dissolution / precipitation and gypsum dissolution,while Na-Ca ion exchange and evaporation concentration effect occurs in the discharge zone,in the slow runoff zone there were a variety of hydro-geochemical cation coexist.

关 键 词：关中盆地 浅层地下水 演化机制 离子交换 蒸发浓缩 

分 类 号：P641.2[天文地球—地质矿产勘探]