关中盆地浅层地下水CFC年龄的计算

CFCs age calculation of shallow groundwater in Guanzhong basin

通过在关中盆地典型地貌系统取样,在实验室中应用吹扫捕集气相色谱法对关中盆地浅层地下水样品CFC-11、CFC-12和CFC-113浓度进行测定,以亨利定律为基础建立了计算地下水CFC年龄的活塞模型。利用CFC输入函数对地下水表观年龄进行了计算。研究结果表明,关中盆地浅层地下水的年龄随埋深增加而增大;从两侧山前向渭河,浅层地下水年龄呈增加的趋势;自然状态下,渭河水对地下水的影响仅局限在河道两侧2km范围内。

Through systematically sampling in some typical regions in Guanzong basin, the concentrations of CFC-11, CFC-12 and CFC-113 of shallow groundwater in Guanzhong basin are determined in the laboratory using a purge and trap chromatography procedure and a Piston-Flow-Model is established to calcuate CFCs ages of groundwater based on the Henry Law. Apparent ages of groundwater are calculated by the input function of CFCs. The study result shows that ages of shallow groundwater in Guanzhong basin increase as depth. From mountain sides to the Weihe river, shallow groundwater ages take a rising trend. Under natural conditions, the Weihe fiver does not affect areas more than 2 kilometers away from the bank.