Separating baseline conditions from anthropogenic impacts: example of the Damour coastal aquifer (Lebanon) |
| |
| Authors: | Wisam M Khadra Pieter J Stuyfzand |
| |
| Institution: | 1. VU University Amsterdam, Critical Zone Hydrology Group, 1081 HV Amsterdam, The Netherlands;2. Department of Geology, American University of Beirut, 1107 2020 Riad El-Solh, Beirut, Lebanonw.khadra@vu.nl;4. KWR Watercycle Research Institute, 3430 BB Nieuwegein, The Netherlands |
| |
| Abstract: | AbstractA new structured approach is presented to derive groundwater baseline conditions, in this case for a dolomitic limestone aquifer suffering from salinization and other anthropogenic impacts. It builds on the HydroChemical System Analysis (HCSA) to map different groundwater bodies (hydrosomes) and hydrochemical zones within them, each of which show significant differences in baseline conditions. It also comprises a rigorous elimination scheme for samples affected by bias or pollution. The method is applied to the Damour coastal aquifer system, south of Beirut (Lebanon). Concentrations of Cl, Cl/Br, 2H, 18O and Ca/Sr were used to discern five hydrosomes and to determine mixing ratios. The dominant hydrochemical facies was (sub)oxic, calcareous and salinized, indicating a very low reduction capacity of the aquifer system, strong dissolution of dolomitic limestone and clear traces of seawater encroachment. The method proposed was capable of filtering out baseline conditions for 16 main constituents, 64 trace elements and two isotopes. |
| |
| Keywords: | baseline chemistry system analysis groundwater mapping multi-tracing salinization Lebanon |
|
|
