陕西“二华”地区浅层地下水循环特征分析

Characteristics of Shallow Groundwater Cycle in Huaxian and Huayin Areas of Shaanxi

运用环境同位素和水化学成分作为水循环研究的示踪剂,揭示了陕西"二华"(华县、华阴)地区浅层地下水循环特征。通过现场调查并对浅层地下水采样,进行室内水化学和氢氧同位素组成测定,分析了浅层地下水氢氧同位素和水化学组成的空间分布规律。结果表明:研究区浅层地下水δ18O、δD分布规律反映降水是浅层地下水主要补给源,其径流方向为由南向北,渭河沿岸地区存在地下水漏斗区,渭河河水侧向补给该区域;水化学特征表现为研究区渭河沿岸水质矿化度较高,为微咸水分布区,靠近秦岭山前、研究区中部矿化度较低,为淡水分布区;研究区地下水硬度普遍偏大,其中下庙街、华阴农场、七连、夫水一带为极硬水分布区,整体上从南向北,水质从硬水过渡到极硬水。

By using environmental isotopes and hydrochemical components as tracers in surveying water circulation, this paper revealed the shallow groundwater circulation characteristics in Huaxian and Huayin areas of Shaanxi. By field surveying and groundwater sampling in the shallow and deep aquifers, the hydrochemistry and hydrogen and oxygen isotope components were measured. Then the spatial distribution rule and evolvement tendency of δD, δ18O and hydrochemieal components of the shallow groundwater were analyzed for revealing the groundwater cycle characteristics of the area. The results indicate that ： the main recharge source of the shallow groundwater in the piedmont region is precipitation, the runoff is from the south to the north, there are groundwater depression cones along the Weihe River and the area are supplied. The hydroehemieal characteristics of the groundwater manifest that the mineralization is high, so is the brackish water distribution areas. On the contrary, the TDS is low near the piedmont of Qinling Mountain and in the central of the research area, where are freshwater distribution areas. The water hardness is generally high in research area where Xiamiaojie, Huaying Farm, Qilian and Fushui are extremely hard water distribution areas. In general, from south to noah, water quality changes from hard water to extremely hard water.