Introducing hydrochemical diagnostic tools to differentiate sources of salinity, Southern Iran

Groundwater quality in Southern Iran is typically degraded by a variety of salinity sources including seawater intrusion, saline lakes, salt diapirs, geothermal springs and groundwater evaporation. Twenty three sampling sites from the five major salinity sources of Southern Iran were sampled in order to evaluate the skill of conventional hydrochemical methods, and to propose new diagnostic tools for differentiation of the salinity sources. The samples were analysed for major ions and minor constituents of lithium, bromide, strontium, boron and more than thirty trace elements. The results indicate that the conventional methods are not practical to differentiate salinity sources of Southern Iran. Ion ratios of Na/Cl, Cl/Br, Li/Cl and B/Cl are more or less useful indicators for primary identification of some salinisation sources. However, the proposed composition binary diagrams of Br/Cl vs. Li/Cl, Sr/Cl vs. Li/Cl, and SO4/Cl vs. Li/Cl and ternary diagrams Li-Cl-Br, Sr-Li-Br and Cl-Li-B are the most feasible and confident tools to differentiate salinity sources of the study area. Finally, investigating the hydrochemical results of saline waters from different countries justifies that our proposed diagrams can be extensively used for differentiation of salinity sources with some calibration especially for the district of evaporation.