Ninety-six water samples were collected in the Xi'an area and analysed for D, T, 18O and 14C. Stable isotope contents of water samples from three aquifers show differences between, and mixing among, the three aquifers; the mixing ratio was 37.4% of phreatic water in the first confined aquifer and 43.8% of first mixed water to the second mixed water in the second confined aquifer. The phreatic water comprised about 43.8% × 37.4% = 16.4% of the second mixed water in the second confined aquifer. After the tritium contents in precipitation in the Xi'an region had been reconstructed by a multiple cell linear regression method, the groundwater velocity in the first confined aquifer was calculated as 30-39 m year-1 from an exponential flow model. A 14C piston flow model gave estimates of average flow velocity in the second confined aquifer of 1.14 year-1. The runoffs in the two aquifers were also calculated.
ASJC Scopus subject areas
- Water Science and Technology