The world is facing an acute shortage of clean and safe freshwater. What are the alternative technologies which can solve this crisis? Briefly discuss any three such technologies citing their key merits and demerits.

The world population is projected to reach approximately 9.7 billion by 2050, significantly increasing demand for freshwater resources.UNESCO notes that, 30% of the world’s aquifers are being over-exploited,particularly in regions like the Middle East, North Africa, and South Asia.

## Reasons for Shortage of Clean and Safe Fresh Water:

• Climate Change Impacts:

• Droughts:The United Nations reported that the number of severe droughts globally hasincreased by over 29% since the 1970s.


• Glacial Retreat:glaciers in the Himalayas havelost more than 40% of their mass over the past 40 year


• Groundwater Depletion

• Over-extraction:InOgallala Aquifer(US) water levels dropped by as much as 30 meters.


• Agricultural Use:Agricultureaccounts for 80% of global freshwater withdrawals, with some regions, like South Asia, relying heavily on groundwater for irrigation.

• Inadequate Water Supply:in India according to NITI Aayog, 40% of urban households lack access to piped water.


• Water Quality Issues:

• Contaminated Water Sources: CPCB reported in 2021 that 70% ofIndia’s surface water iscontaminateddue to industrial discharge, agricultural runoff, and untreated sewage.


• Health Risks:According to WHO,waterborne diseaseslike diarrhea, cholera, and dysenteryaffect 2.3 billion people annually.

## Alternative Technologies which can solve this issue:

• Solar Desalination –uses solar energy to evaporate and condense seawater, producing freshwater. This process mimics the natural water cycle, where the sun’s energy evaporates water, which is then condensed into clean water.

• Merits:Environmentally friendly, using renewable energy and Suitable for remote, off-grid locations.


• Demerits:Limited water output compared to conventional desalination plants and  Initial investment costs for solar infrastructure are high.

• Atmospheric Water Generation (AWG) –extracts water from the moisture in the air through condensation. Devices can be designed to capture water by cooling the air or by using desiccants that absorb moisture.

• Merits:Produces clean drinking water from the atmosphere, reducing dependence on surface or groundwater and Can be used in off-grid locations with solar-powered AWG units.


• Demerits:Limited output in areas with low humidity and High energy demand for cooling and dehumidification processes.


• Fog Harvesting –capturing water droplets from fog using large mesh nets. The droplets condense on the mesh and are collected in containers for use.

• Merits:Provides water in arid, foggy regions where other sources are limited and Low-tech and low-energy solution, relatively inexpensive to set up.


• Demerits:Only viable in regions with frequent fog and Limited water output, making it impractical for large-scale use.

A combination of these solutions, along with improved water management and policy frameworks, is essential for ensuring water security and achievingSDG 6.

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