济源盆地地表水和地下水的水化学及氢、氧同位素特征

Characteristics of hydrochemistry and stable hydrogen,oxygen isotopes in surface water and groundwater in Jiyuan Basin

运用氢氧同位素和水化学成分作为水循环过程的示踪剂,研究济源盆地地表水和地下水之间的转化关系.通过现场调查,系统地采集了该区浅层、中深层地下水和河水样品,并在实验室进行了水化学成分(K+、Na+、Ca2+、Mg2+、Cl-、SO2-4、HCO-3)和氢氧稳定同位素组分(D、18O)测定.基于水化学和同位素测定结果,揭示盆地地表水和地下水循环特征.水化学分析结果显示,济源盆地水体的水化学类型主要为HCO3-SO4-Ca-Mg,属于低矿化度水,浅层地下水和河水联系紧密,不同水体水化学成分主要受到岩石风化作用的影响.氢氧稳定同位素研究表明,大气降水是盆地不同水体的主要补给源,地下水在接受降水的补给后经过了不同程度的蒸发作用,中深层地下水受蒸发影响较小,浅层地下水和河水受蒸发影响较大.浅层地下水和河水的主要补给方式是地表大气降水的垂直渗入补给,中深层地下水接受北部太行山区的径流补给,补给高程为620—1185 m.

In the present study,hydrochemical components（ K＋,Na＋,Ca2＋,Mg2＋,Cl-,SO2-4,HCO-3） and environmental isotopes（ D,18O） were used as tracers to investigate the transformation relationship between surface water and groundwater in the Jiyuan Basin. We collected a total of 47water samples from rivers,shallow groundwater and deep groundwater for analysis. The results of hydrochemical study show that the main water type in the Jiyuan Basin is HCO3-SO4-Ca-Mg. Shallow groundwater and river water are closely connected. The hydrochemistry of different water bodies are mainly influenced by rock weathering. The results of deuterium and oxygen-18 analysis reveal that the precipitation is the main recharge source of various water bodies,and evaporation process took place after groundwater recharge from rainfall in the basin. Mild evaporation process occurred in the deep ground water,and intense evaporation process accured in the shallow groundwater and river water. The main recharge way for shallow groundwater and river water is through vertical meteoric precipitation infiltration,while the deep groundwater mainly accepts the recharge of water from Taihang mountains area at the altitude of 620—1185 m.