Water Stress (HL) (DP IB Environmental Systems & Societies (ESS))

Water Stress

What is water stress?

• Water stress is a measure of water supply that considers not only the amount of available water but also the water’s quality, environmental flows, and accessibility

  • Environmental flows refer to the amount of water needed in rivers, lakes, and wetlands to support healthy ecosystems

    • If over abstraction occurs (for irrigation or industry), ecosystems may suffer, leading to the degradation of habitats and loss of biodiversity

    • Healthy ecosystems, such as wetlands and rivers, need adequate water to maintain fish populations, provide clean water, and support other species

  • Accessibility refers to whether people can actually access clean, usable water, even if it exists in the local environment

    • Factors affecting accessibility include infrastructure, such as pipes and wells, the distance to water sources, and whether water is affordable

    • In some regions, water is abundant but not accessible due to a lack of infrastructure or high costs

    • In other regions, water may be available but not clean enough for human consumption

• Water stress differs from water scarcity

  • Water scarcity only considers the absolute shortage of water in a region

  • Even if a region has sufficient water, it may experience water stress if the water is polluted or difficult to access

Measuring water stress

• Water stress is defined as a situation where the available clean, accessible water supply is less than 1 700 cubic metres per person per year

  • This figure includes the water needed for:

    • Personal use

    • Other sectors, such as agriculture and industry

Causes of water stress

• Industrialisation in emerging economies:

  • As countries rapidly industrialise, the demand for water increases to support:

    • More factories

    • Greater energy production

    • Increasing urbanisation

  • For example, China has experienced water stress in its northern regions due to its rapid industrial growth

    • This is made worse due to limited freshwater sources in these areas

    • One major cause is that factories demand significant water for cooling and processes

    • This has led to competition with local agriculture and domestic use

• Population pressure and over-abstraction in low-income countries:

  • Population growth puts huge pressure on existing water supplies

    • Especially in countries with limited infrastructure to store and distribute water

  • For example, India faces water stress due to over-abstraction of groundwater in many regions

    • Especially in rural areas where agriculture depends heavily on underground water sources

    • The fast-growing population is making this problem worse

Water stress and transboundary disputes

• When rivers, lakes, or other water sources cross regional or national boundaries, disputes can arise over access and control

  • For example, the Nile River flows through 11 countries

  • Disagreements, particularly between Egypt and Ethiopia, have intensified over Ethiopia's construction of the Grand Ethiopian Renaissance Dam

  • Egypt, which is highly dependent on the Nile for agriculture and drinking water, fears reduced flow downstream

• Political, historical, and environmental tensions often make these disputes even more complicated

Impacts of water stress

• Agricultural impact:

  • Water stress can reduce crop yields due to lack of sufficient irrigation water, leading to food insecurity

• Economic impact:

  • Water shortages can disrupt industries, particularly those requiring significant water inputs like energy, textiles, and food production

• Health impact:

  • Low water quality in stressed regions leads to diseases like cholera and dysentery due to lack of clean drinking water