贺兰山以北乌兰布和沙漠地下水水化学特征演化规律研究  

Study of the evolution of hydrochemical properties of groundwater in Ulan Buh Desert in the north of the Helan Mountains

作　　者：党慧慧[1] 董军[1] 岳宁[1] 董阳[1] 郭映[1] 魏国孝[1] 

机构地区：[1]兰州大学资源环境学院西部环境教育部重点实验室,甘肃兰州730000

出　　处：《冰川冻土》2015年第3期793-802,共10页Journal of Glaciology and Geocryology

基　　金：国家自然科学基金项目(41471023)资助

摘　　要：乌兰布和沙漠对中国西北部干旱地区气候变化和水文循环过程研究具有指示意义,以水文地球化学运移为导向,通过分析33个地下水样,探讨了该区地下水的补给与演化过程.结果表明:巴彦乌拉山浅层地下水水化学类型为Cl--HCO-3-SO2-4-Na+;从吉兰泰盐湖至乌兰布和沙漠,主要水化学类型变化浅层地下水为Cl--HCO-3-Na+到Cl--HCO-3-SO2-4-Na+,深层地下水为HCO-3-Cl--Na+再到HCO-3-Cl--Na+或HCO-3-Cl--Ca2+.Gibbs图表明,研究区地下水的水化学特征主要受蒸发浓缩作用影响和岩石风化作用控制,大气降雨机制影响甚微.主要离子相关关系图及饱和指数表明,岩盐、芒硝、钠长石、方解石、白云石、石膏等矿物的风化溶解是该区地下水主要离子来源.此外,氯碱指数和Ca/Na的指示,说明阳离子交换作用也是形成该地区地下水水化学组分的重要机制.The Ulan Buh Desert has significant effect for the climate change and hydrologic cycle process in Northwest China. In this paper,evolution of the groundwater in the Ulan Buh Desert was studied based on hydrogeochemical analyses results. A total of 33 representative groundwater samples were collected from different wells to monitor the variation of water chemistry. Based on hydrogeochemical analysis,it is revealed that shallowgroundwater chemical type in the Bayan Ulan M ountains piedmont is Cl^--HCO3^--SO4^2--Na^＋; from Jilantai Lake to Ulan Buh Desert,shallowgroundwater evolves from Cl^--HCO3^--Na^＋type to Cl^--HCO3^--SO4^2--Na^＋type,and deep groundwater changes from HCO3^--Cl^--Na^＋type to HCO3^--Cl^--Na^＋and then to HCO3^--Cl^--Ca^2＋. Gibbs plot shows that groundwater chemistry in Ulan Buh Desert is mainly controlled by evaporation and dissolution of many minerals,with slight contribution of precipitation. Relations between major cations and anions and saturation indices showthat major sources of ions in the study area are mainly the dissolution of halite,Glauber＇ s salt,albite,calcite,dolomite,gypsum. In addition,chloro alkaline indices and Ca / Na ratio also demonstrate that ion exchange is a major mechanism controlling the composition of groundwater.

关 键 词：水文地球化学特征 Gibbs图 氯碱指数 饱和指数 乌兰布和沙漠 

分 类 号：P641.3[天文地球—地质矿产勘探]