salinisation

Salinisation is the process by which the salt content of soil or water increases. This can occur naturally or be exacerbated by human activities. In soils, salinisation leads to a buildup of soluble salts in the root zone, which can hinder plant growth by making it difficult for plants to absorb water due to osmotic pressure. It can also lead to direct toxicity to sensitive plant species.

Natural salinisation often happens in arid and semi-arid regions where evaporation rates are high, drawing saline groundwater to the soil surface. Precipitation of salts then occurs as the water evaporates. Human-induced salinisation is a significant environmental concern, often linked to irrigation practices. When irrigation water, which typically contains dissolved salts, is applied to land, and subsequent evaporation or transpiration removes the water, the salts are left behind. If drainage is poor, these salts accumulate over time. Over-irrigation and the use of saline irrigation water are common contributors.

In aquatic environments, salinisation refers to the increase in salt concentration in freshwater bodies, such as rivers, lakes, and groundwater aquifers. This can be caused by the intrusion of seawater into coastal freshwater systems, particularly in areas with heavy groundwater extraction or altered river flows. Rising sea levels can also contribute to coastal salinisation. The consequences of salinisation include degraded agricultural land, loss of biodiversity, and reduced availability of fresh drinking water.