内蒙古河套平原水体同位素及水化学特征  

Characteristics of Water Isotope and Hydrochemistry in Hetao Plain of Inner Mongolia

作　　者：汪敬忠[1,2] 吴敬禄[1] 曾海鳌[1] 白瑞东[1,2] 

机构地区：[1]中国科学院南京地理与湖泊研究所湖泊与环境国家重点实验室,江苏南京210008 [2]中国科学院大学,北京100049

出　　处：《地球科学与环境学报》2013年第4期104-112,共9页Journal of Earth Sciences and Environment

基　　金：国家重点基础研究发展计划("九七三"计划)项目(2011CB403301;2012CB956102);"西部之光"人才培养计划项目(XBBS201106);王宽城博士后基金项目(20110491752)

摘　　要：运用环境同位素和水化学技术,结合现场调查和室内分析,分析了河套平原不同类型水体氢、氧同位素和水化学特征,讨论了不同水体受蒸发浓缩和人类活动的影响,并利用氢、氧同位素示踪地下水的补给来源。结果表明:河套平原大气降水线斜率小于全球大气降水线斜率,不同水体的氘过量参数小于包头地区大气降水线和全球大气降水线,反映水体的蒸发作用导致氢、氧同位素的富集;河水、湖水以及地下水的氢、氧同位素组成变化差异明显,而且从湖水到河水再到地下水,氢、氧同位素组成有逐渐贫化的趋势;不同水体的水化学类型明显不同,河水主要为HCO3-Ca型,地下水主要为HCO3-Na、HCO3-Ca以及Cl-Na型,湖水为SO4-Mg和Cl-Na型;地下水与河水的氢、氧同位素组成和各离子质量浓度的相关性差,湖水的氢、氧同位素组成与K+、Ca2+、Mg2+、Na+、Cl-、SO2-4质量浓度,pH值,电导率以及矿化度则存在显著的相关性;河套平原南侧与西部地区地下水主要靠黄河水补给,北侧主要受降水和山前流水的侧向补给,而东部靠近乌梁素海地区的地下水氢、氧同位素组成和矿化度偏高,可能受湖水的影响较大。Based on the field survey and experiment, the characteristics of hydrogen and oxygen isotopes and hydrochemistry for different waters in Hetao Plain were analyzed by the means of environmental isotope and hydrochemistry technology, the effects of evaporation concentration and human activity on different waters were discussed, and groundwater recharge sources were traced by hydrogen and oxygen isotopes. The results show that slope of meteoric water line in Hetao Plain is less than that of global meteoric water line, and deuterium excess parameters of different waters are less than that of meteoric water line in Baotou area and global meteoric water line, so that water evaporation results in the enrichment of hydrogen and oxygen isotopes; changes of hydrogen and oxygen isotopic compositions of river water, lake water and groundwater are significant, and the isotopic compositions are gradually depleted from lake water to river water, and then to groundwater; hydrochemical types are HCOa-Ca for river water, HCO3-Na, HCOa-Ca and C1-Na for groundwater and SO4-Mg and Cl-Na for lake water; correlations between hydrogen and oxygen isotopic compositions of river water and groundwater and mass concentrations of different ions are not significant, but hydrogen and oxygen isotopic compositions are significantly correlated with mass concentrations of K＋, Ca2＋, Mg2＋, Na＋, Cl- and SO42- , pH, conductivity and salinity of lake water; Yellow River water recharges the groundwater in the southern and western of Hetao Plain, and rainfall and piedmont flowing water laterally recharge the groundwater in the north, but hydrogen and oxygen isotopic compositions and mineralization of groundwater in the east are higher near Ulansuhai area, because the effect of lake water is probably significant.

关 键 词：氢、氧同位素 水化学 大气降水线 蒸发作用 分馏 地下水补给 河套平原 内蒙古 

分 类 号：P641.3[天文地球—地质矿产勘探]