Estimation of shallow groundwater ages and circulation rates in the Henan Plain, China: CFC and deuterium excess methods

摘要: CFC age and deuterium excess methods were applied to the estimation of groundwater circulation rates in Quaternary shallow system Henan Plain. The results provide a basis for renewability evaluation. spatial distribution shows that mainly comprises modern water, less than 50 a. 30 was piedmont zone Taihang, Funiu, Dabie Mountains, indicating short residence times, fast cycling, with 27–31 m/d. Groundwater cycling along Yellow River also rapid because exchange River. 34–54 In areas around Tongxu, Shangqiu, Taikang, Xiangcheng, middle study area, east Huaxian-Changyuan Xixian, Gushi south, 30–40 a, suggesting longer time. cycle these slower piedmonts, area 15–26 Luyi, Yongcheng, Zhumadian, Xincai Huaibin, older 40 longest times slowest (∼12 m/d). correlation between averages northern, central, southern systems divisions strong (R = 0.9714), showing time embodied by parameter consistent estimated using method.