Where are the world’s water stresses?

Where are the world’s water stresses?

Subject: Geography

Section: Hydrology

Context:

• There is a contentious domestic debate over water supplies. Disruptions to water supply or perceived misuse can cause immediate social unrest, and countries like U.S., Australia, Iran and France have seen violent protests regarding water recently.

Details:

• Constant and affordable access to fresh water is recognised as a basic human right by the UN.
• Freshwater provides a foundation for life and is also crucial for industry and manufacturing, energy production, agriculture, sanitation, and other essential societal functions.

Threat to water availability:

• Desertification, climate change, man-made water diversion, dam building, pollution, and overuse have seen rivers, lakes, and aquifers dry up.
• Poor water management and infrastructure:
  • In Iraq, up to 14.5 per cent of the country’s water is lost to evaporation and two-thirds of its treated water is lost due to leaks and poor infrastructure.
  • Up to 25 to 30 per cent of South Africa’s water is lost to leaks, while even in many industrialised countries, up to 15 to 20 per cent of water supply is lost.
• Water inequality:
  • In South Africa, 14 per cent of the population has been found to be responsible for more than half of the freshwater use.
  • Across Africa, one in three people already faces water scarcity, where “the availability of natural hygienic water falls below 1,000 m3 per person per year.”
• Water privatization:
  • Monetisation has even seen countries like Fiji, the world’s 4th-largest water exporter in 2021, face water supply shortages over the last few years.
• Water contamination:
  • Contamination can lead to longer-term damage to public faith in water infrastructure.
• Water security:
  • The US and Mexico have historically competed over water rights to both the Colorado River and the Rio Grande.
  • Tension between Iran and Iraq over Tigris and Euphrates rivers and their tributaries.
  • Relations between Egypt, Sudan, and Ethiopia have similarly deteriorated since the latter began construction of the Grand Ethiopian Renaissance Dam (GERD) in 2011.

Water desalination:

• A desalination plant turns salt water into water that is fit to drink.
• Desalination is the process of removing salts from water to produce water that meets the quality (salinity) requirements of different human uses.
• The most commonly used technology for the process is reverse osmosis.
  • External pressure is applied to push solvents from an area of high-solute concentration to an area of low-solute concentration through a semi-permeable membrane.
  • The microscopic pores in the membranes allow water molecules through but leave salt and most other impurities behind, releasing clean water from the other side.
• These plants are mostly set up in areas that have access to seawater.
• Although seawater desalination remains expensive and energy-intensive, it is becoming more efficient and widespread.
• In Saudi Arabia, 50 per cent of the country’s water needs are met by desalination, while Egypt plans to open dozens of new desalination plants in the coming years.
• Currently, 70 per cent of the world’s desalination plants are found in the Middle East.

Advantages of Desalination Plants:

• It can extend water supplies beyond what is available from the hydrological cycle, providing an “unlimited”, climate-independent and steady supply of high-quality water.
• It can provide drinking water in areas where no natural supply of potable water exists.
• As it generally meets or exceeds standards for water quality, water desalination plants can also reduce pressure on freshwater supplies that come from areas (over-exploited water resources) that need protection.

Disadvantages of Desalination Plants:

• Costly to build and operate desalination plants as the plants require huge amounts of energy.
• Energy costs account for one-third to one-half of the total cost of producing desalinated water.
• Because energy is such a large portion of the total cost, the cost is also greatly affected by changes in the price of energy.
• The environmental impact is another disadvantage to water desalination plants. Disposal of the salt removed from the water is a major issue.
• This discharge, known as brine, can change the salinity and lower the amount of oxygen (Hypoxia) in the water at the disposal site, stressing or killing animals not used to the higher levels of salt.
• In addition, the desalination process uses or produces numerous chemicals including chlorine, carbon dioxide, hydrochloric acid and anti-scalents that can be harmful in high concentrations.