Geochemical And Isotopic Characterization Of Groundwater In Tecate, Baja California, Mexico

Environmental isotopes and hydrochemistry are useful tools for the study of groundwater flow systems. Groundwater from Tecate area in Peninsula of Northern Baja California, Mexico, was sampled for chemical and stable isotopes analyses. Four groundwater types were identified, predominating the Mixed-HCO3 facie. A tendency of calcium to the sodium and bicarbonates to sulphates is noted. The Na+/Cl-and (Ca+2 + Mg+2)/(SO42-+ HCO3-) ratios reveal an input of sodium to the system which can be related to water-rock interaction and Na-Ca exchange. The delta H-2 vs delta O-18 plot shows that evaporation has occurred during recharge, indicating that groundwater is derived from modern precipitation that is subjected to evaporation during its passage through the soil and unsaturated zone to reach the water table. In general, there is a trend of groundwater chemistry to be modified by anthropogenic processes towards the western portion. (C) 2017 The Authors. Published by Elsevier B.V.