Salinization and Saline Environments

This chapter provides an overview of global salinization phenomena and investigates the different mechanisms and geochemical processes that are associated with salinization. The overview includes salinization of rivers, lakes, and groundwater from different parts of the world. Special emphasis is given to the distinction between natural processes and anthropogenic forcing that generates salinity, such as wastewater contamination and agricultural runoff. As such, two anthropogenic salinization cycles are introduced - the agricultural and the domestic. The role of the unsaturated zone in shaping the chemical composition of dryland salinization is also discussed. An overview of the effects of salinity on the occurrence of health-related contaminants such as fluoride, oxyanions (arsenic, selenium, boron), radionuclides, trihalomethanes, and fish-kill algae is presented. Some useful geochemical and isotopic fingerprinting tracers are introduced for elucidating the salinity sources. Finally, the chemical and isotopic compositions of man-made 'new water' that is produced from desalination are analyzed with implications for predicting the chemical and isotopic compositions of future water resources in the Anthropocene Era.