阿拉善塔木素地段地下水补给来源与演化特征分析  

ANALYSIS OF RECHARGE SOURCES AND HYDROGEOCHEMICAL PROPERTIES OF GROUNDWATER IN TAMUSU,ALXA,INNER MONGOLIA

作　　者：王礼恒[1] 董艳辉[1,2] 周鹏鹏 张江义 宋凡[5,6] 魏亚强 WANG Liheng;DONG Yanhui;ZHOU Pengpeng;ZHANG Jiangyi;SONG Fan;WEI Yaqiang(Key Laboratory of Shale Gas and Geoengineering,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029;College of Earth Sciences,University of Chinese Academy of Sciences,Beijing 100049;School of Water Resources and Environment,China University of Geosciences(Beijing),Beijing 100083;Key Laboratory of Cenozoic Geology and Environment,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029;Hydrology and Water Resources Monitoring and Forecasting Center,The Ministry of Water Resources of the People's Republic of China,Beijing 100053;National Groundwater Monitoring Center,The Ministry of Water Resources of the People's Republic of China,Beijing 100053;Chinese Academy of Environmental Planning,Beijing 100012)

机构地区：[1]中国科学院地质与地球物理研究所,中国科学院页岩气与地质工程重点实验室,北京100029 [2]中国科学院大学,地球科学学院,北京100049 [3]中国地质大学(北京),水资源与环境学院,北京100083 [4]中国科学院地质与地球物理研究所,新生代地质与环境院重点实验室,北京100029 [5]水利部信息中心(水利部水文水资源监测预报中心),北京100053 [6]水利部水文水资源监测评价中心(水利部国家地下水监测中心),北京100053 [7]生态环境部环境规划院,北京100012

出　　处：《工程地质学报》2019年第3期691-698,共8页Journal of Engineering Geology

基　　金：国家自然科学基金项目(41702273);国防科工局高放废物地质处置研究开发项目“内蒙古阿拉善高放废物地质处置备选场址预选及评价研究”资助~~

摘　　要：内蒙古阿拉善塔木素地区是我国高放废物地质处置预选地段之一,开展相应的水文地质特性评价研究对于科学评估其适宜性尤为重要,而充分认识地下水的补给来源与演化过程是了解地下水的形成机制与更新能力的基础。结合塔木素地区水文地质条件,利用水化学与同位素技术对研究区26组水样进行分析,结果显示:研究区地下水氢氧同位素与西北地区大气降水氢氧特征类似,表明区内地下水主要受到当地大气降水补给,这也与水文地质条件认识相符;区内地下水呈现高矿化度特征,TDS均值达到了2.9g·L^-1,地下水化学类型为Na^+-Cl^-型,表现出干旱区地下水的典型特征;此外,地下水的氯碱指数均大于0,且Mg^2++Ca^2+-HCO3^--SO4^2-与Na^++K^+-Cl^-呈线性关系且斜率接近-1,说明了阳离子交换反应普遍发生在地下水化学演化过程中。塔木素重点地段地下水属于不适宜利用的高矿化度地下水,且深部地下水年龄大于5000年,循环交替能力较差。这一认识为该地段处置库选址和场址评价提供了重要的水文地质依据。Tamusu,located in Alex,Inner Monglia,northwestern China,is one of the preselected area for high-level radioactive waste geologic disposal of China.Carrying out hydrogeological assessment at potential disposal sites of interest is particularly important for getting scientific results of suitability.In particular,knowing about recharge sources and evolution processes of groundwater will help to further understand the formation and renewal of groundwater.Combining the hydrogeological conditions in Tamusu area,using hydrogeochemical and isotopic techniques to get the results of 26 specimens which were collected from the study area.The results show that groundwater in the study area mainly originated from local precipitation because there was similar isotopic characteristics between them.It is also consistent with the hydrogeological conditions in the study area.The typical feature of groundwater is high salinity and the TDS average value is about 2.9 g·L^-1.Meanwhile,almost all samples were Na^+-Cl^-type.This is a common phenomenon in arid regions.Moreover,two chloroalkaline indices of groundwater are positive and there are good linear relationship between Mg^2++Ca^2+-HCO3^--SO4^2-and Na^++K^+-Cl^-with a slope of-1.This indicates that ion exchange is a significant geochemical process for controlling the composition of groundwater.The groundwater in study area is not fit to drink due to high salinity and the age of deep groundwater older than 5000 a because of weak renewal.This cognition provides crucial hydrogeological evidences for site selection and evaluation in the area.

关 键 词：地下水 水化学特征 氢氧稳定同位素 阿拉善 核废料地质处置 

分 类 号：P641.3[天文地球—地质矿产勘探]