Age Correction of the Groundwater in North China Plain
华北平原地下水年龄校正

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.