东阿县沿黄区孔隙地下水化学特征及成因分析

Chemical Characteristic of Groundwater in Porous Aquifer and Its Cause Near Yellow River in Dong’e County

基于东阿县牛角店镇、乐平铺镇等地区38组孔隙水样品和3组黄河水样品,采用水化学离子比法和氢氧同位素分析法,系统分析了东阿县沿黄区孔隙水化学特征的形成机理及黄河水对孔隙水的影响。结果表明,研究区孔隙地下水以HCO_(3)-Na型为主,含水层中主要发生硅酸盐岩溶解和碳酸岩溶解过程;黄河水入渗、大气降水的入渗和水-岩相互作用是区内地下水化学成因的主导因素;区内地下水化学与同位素特征反映出研究区内黄河影响带范围在18 km以内,影响带范围内地下水参与外界循环不积极,主要受黄河水的补给,地下水化学组成主要受黄河水和水-岩相互作用的影响,在影响带范围外地下水化学组成受到大气降水的影响程度增大。

The hydrochemistry characteristic of groundwater in porous aquifer and its mechanism of formation in the Niujiaodian town and Lepingpu town of Dong’e County were studied based on the 38 groundwater samples from porous aquifer and 3 samples from Yellow River. The results show that the HCO_(3)-Na was the main type in the study area, and the dissolution of silicate and carbonate minerals was the main chemical reaction in the aquifers. The infiltration of the Yellow River water and precipitation, and the water-rock interaction were the main factors influencing the groundwater chemical composition. The hydrochemical and isotopic characteristics of water samples showed that the influence zone of the Yellow River was within 18 km. The groundwater within the influence zone was not actively involved in the external water circulation, and the groundwater were mainly recharged by the Yellow River water. The Yellow River water and water-rock interaction influenced the chemical composition of groundwater within the influence zone. In the areas out of the influence zone, the groundwater chemical and isotopic composition were influenced obviously by the precipitation.