Groundwater in saline water belts becomes saline primarily through natural processes involving the concentration of salts and interaction with surrounding materials, along with potential human-induced factors in specific areas like coastlines.
Natural Processes Contributing to Salinization
Water naturally picks up soluble salts as it travels through the ground.
- Collection of Soluble Salts: As water moves through the landscape and soil, it naturally collects soluble salts, predominantly sodium chloride. This dissolution of salts from the geological formations and soils increases the salinity of the groundwater over time.
- Salinization Due to Evaporation: Groundwater can become saline due to evaporation. In areas with high evaporation rates, especially where the water table is shallow, water evaporates from the surface or near-surface layers, leaving dissolved salts behind. This process concentrates the salts in the remaining groundwater, increasing its salinity.
Human Impact in Coastal Saline Areas
In specific environments, human activities can significantly worsen or induce groundwater salinization.
- Coastal Saltwater Intrusion: In coastal areas, intensive human use of a groundwater source, such as excessive pumping for irrigation or municipal supply, can lower the groundwater level. This can cause the natural direction of groundwater seepage towards the ocean to reverse. When the flow direction reverses, saltwater from the ocean is drawn inland into the freshwater aquifer, a process known as saltwater intrusion, which causes the groundwater to become saline and can also lead to soil salinization.
These mechanisms, particularly the natural collection of salts from the ground and concentration through evaporation, contribute to the formation and characteristics of saline water belts.
