Salinity is the state of the water in terms of salts. The higher the salinity, the more salt content there is in water. It may be defined differently based on various parameters like temperature, specific gravity, pressure, etc. Saline drainage is saline water that drains into an area or region.
The term “saline groundwater” refers to groundwater with high salinity along with dissolved solids like sodium, chloride and bicarbonate (or other ions).
Typically this type of groundwater is found closer to the coasts, but it may also be found in areas like caves due to active dissolution processes.
The highest salinity is observed between 20° N and 40° N (36‰) because this zone is characterized by high temperature, high evaporation but relatively low rainfall
The average salinity of 35‰ is recorded between 100 -300 latitudes in the southern hemisphere
The zone between 40 deg -60 deg latitudes in both the hemispheres records low salinity where it is 31‰ and 33‰ in the northern and the southern hemispheres respectively.
Salinity further decreases in the polar zones because of influx of Glacial melt-water. On an average, the northern and the southern hemispheres record average salinity of 35‰ and 34‰ respectively.
