Application of the environmental isotopes to the hydrogeological study of the coastal sector in the Buenos Aires province, between Cabo San Antonio and Bahia Blanca. Final report for the period December 1984 - December 1989

Results and conclusions obtained under the framework of the 3995/RB research contract between the IAEA and the INGEIS with participation of the Dirreccion de Geologia, Mineria y Aguas Subterraneas (DGMAS) and the Centro Federal de Inversiones (C.F.I.) are presented. From the results the suitability of the isotope techniques for tracing hydrodynamic processes could be confirmed. Recharge condition also have been defined. The exceptional event of flood in the Buenos Aires province that begin in 1986 in connection with abnormal high precipitations targed infiltrating waters with the isotopical signal of the evaporation. This signal was found out in many of the sampled wells and allowed to recognize the recharge, even to significant depths. In the Pinamar and Villa Gesell towns, it was possible to establish the dynamic of wells under seasonal exploitation. In the most of cases water withdrawn in summer was recharged in the immediate precedent pluvious period. Refs, figs and tabs