Chapter 7. Practical applications of CFCs in hydrological investigations

In an aquifer of constant thickness and receiving constant recharge, the groundwater age will increase exponentially with depth below the water table. If the groundwater age is measured at any discrete depth, then it is possible to calculate the groundwater recharge rate. In practice, collection of a number of samples at discrete depths close to the water table is preferred, and vertical groundwater velocities can then be directly determined from the vertical CFC age gradient. The aquifer recharge rate can be determined from this data, provided that the aquifer porosity is known or can be estimated