华北平原地下水年龄校正

地下水14C年龄一般指地下水和土壤CO2隔绝至今的年代.地下水测年在地下水水文学中占有特殊的位置,地下水测年可以用来确定补给区,估算地下水流速度、流量、补给速率、水力传导系数和有效孔L隙度,而且年龄数据还可以用来完善地下水流模型.本研究选择华北平原为重点研究区,利用地下水中的同位素和化学组分的测试结果,应用水文地球化学及同位素水文学等相关知识,通过六种传统模型和反向质量平衡模型(NETPATH)对华北平原地下水年龄进行校正.根据年龄校正结果,分析了深层地下水的年龄变化特点,确定了水流路径上发生的水文地球化

Age Correction of the Groundwater in North China Plain

The groundwater 14C age generally refers to the years since the isolation of groundwater from soil gas CO_2.Radiometric 14C dating of groundwater possesses a special position in groundwater hydrology because of enormous potential rewards afforded by the age data.The age data can be used to locate the recharge area and estimate such parameters as groundwater flow directions and velocities,fluxes,recharge rates,hydraulic conductivities and effective porosities.Besides,any additional constraints derived from 14C data can improve flow models based on the hydraulic data alone.With the North China plain as a key study area,the authors,using the measuring and testing results of isotopic and chemical compositions in groundwater,carried out age correction studies on the basis of the knowledge of hydrogeochemistry and isotopic hydrogeology.The groundwater age of the North China plain was corrected with six traditional models and the inverse mass-balance model(NETPATH).The results can be used to analyze the age variation of groundwater in deep confined aquifers and decide the hydrogeochemical reactions along the flow path.It is held that groundwater in the deep confined aquifer beneath the central and littoral plain is a nonrenewable resource.