Salinization, a grave environmental and agricultural concern, refers to the accumulation of soluble salts in soil and water, leading to a decrease in soil fertility and rendering it unsuitable for crop production. The primary causes of salinization include natural processes, like the weathering of parent rocks, and human interventions, such as poor irrigation practices, deforestation, and the excessive extraction of groundwater. Over time, as salts accumulate at the surface due to evaporation, the once fertile lands transform into barren expanses. This phenomenon directly threatens food security, biodiversity, and the livelihoods of millions, particularly those in arid and semi-arid regions.
Understanding the ramifications of salinization becomes imperative when analyzed in the context of the United Nations' Sustainable Development Goals (SDGs). These 17 interconnected goals, established in 2015, strive for a better and more sustainable future, touching various spheres from poverty and health to environment and economic growth. Salinization impacts multiple SDGs, but its relationship with SDG 2 (Zero Hunger), SDG 6 (Clean Water and Sanitation), and SDG 15 (Life on Land) is most profound.
SDG 2 aims to eradicate all forms of hunger and malnutrition, ensuring that everyone has access to sufficient, nutritious food year-round. Salinization stands as a roadblock to achieving this objective. As saline soils reduce crop yields and increase production costs, food availability and affordability are directly compromised. This is especially concerning for countries that depend largely on agriculture for their sustenance and economy. Without timely interventions, increasing soil salinity can push many back into the clutches of hunger and poverty.
SDG 6 emphasizes the importance of ensuring the availability and sustainable management of water for all. Salinization contributes to the degradation of freshwater resources, making it even harder to achieve this goal. When irrigation practices are not appropriately managed, saline waters seep into freshwater sources, making them unsuitable for consumption and agriculture. Moreover, as aquifers are over-extracted, a process known as sea water intrusion can occur in coastal regions, further salinating freshwater reserves. Thus, the balance and health of our water ecosystems are threatened by the specter of increasing salinity.
Lastly, SDG 15, which focuses on the protection, restoration, and sustainable use of terrestrial ecosystems, also intersects with the challenge of salinization. As salt-affected soils spread, terrestrial biodiversity takes a hit. Flora and fauna native to these lands either migrate or perish, leading to diminished ecosystem health and resilience. The effects of salinization also exacerbate land degradation, a concern directly addressed under this goal.
As sea level rise drives saltwater farther inland, drinking water supplies of some coastal cities will be contaminated. This paper evaluates how climate change is shifting the location of ‘salt lines,’ the zone where coastal fresh water meets the ocean, and implications for drinking water management. It focuses on changes from climate, as opposed to water overuse or water quality mismanagement, and reviews recent literature along three dimensions. Firstly, the paper reviews regulations on salinity in drinking water.
Climate change has affected diverse spheres and its impact is being witnessed worldwide. Soil, the basis of human sustenance, is both directly and indirectly affected by climate change. Soil erosion, vegetation degradation and soil salinisation are becoming prevalent, causing a threat to future food security. Saline soils are found mainly in North and Central Asia, Africa and South America. Various factors such as excess irrigation and poor drainage, groundwater salinity, sea level rise and intrusion, irregular rainfall contribute to the process of soil salinisation.
Soil and water salinity and associated problems are a major challenge for global food production. Strategies to cope with salinity include a better understanding of the impacts of temporal and spatial dynamics of salinity on soil water balances vis-à-vis evapotranspiration (ET) and devising optimal irrigation schedules and efficient methods. Both steady state and transient models are now available for predicting salinity effects on reduction of crop growth and means for its optimization.
