Addressing Water Scarcity (DP IB Environmental Systems & Societies (ESS))

Revision Note

Alistair Marjot

Expertise

Biology & Environmental Systems and Societies

Addressing Water Scarcity

  • Water is unevenly distributed around the globe

  • There are significant areas of water surplus  and water deficit

  • Around 450 million people in LICs suffer from severe water shortages

  • Around 1.2 billion live in areas of water scarcity

  • Physical water scarcity occurs where demand for water outstrips supply, often due to arid climate and low rainfall

  • Economic water scarcity is where water is available but people can’t afford it or the infrastructure is inadequate

World map showing water scarcity levels: blue for little/no scarcity, yellow for physical scarcity, orange for approaching scarcity, red for economic scarcity, and white for not estimated.
Global pattern of water scarcity

Water conservation techniques

Domestic Water Conservation Techniques

Technique

Description

Metering

Install water metres to monitor and control water usage accurately

It helps households track their consumption

Rationing

Set limits on water usage per household

This can involve implementing quotas or tariffs based on usage levels

Grey-water Recycling

Capture and treat greywater for reuse in non-potable applications like toilet flushing or outdoor irrigation

Low-flush Toilets

Install toilets with low-flow mechanisms to reduce water usage per flush

Rainwater Harvesting

Collect and store rainwater for tasks such as watering gardens or washing vehicles.

Industrial Water Conservation Techniques (Food Production Systems)

Technique

Description

Greenhouses

Use greenhouses equipped with large-scale rainwater harvesting systems to irrigate the crops grown inside)

Aquaponics Systems

Integrated aquaponics systems combine fish farming with hydroponic plant cultivation

These closed-loop systems recycle water between fish tanks and plant beds, reducing overall water consumption

Drip Irrigation

Install agricultural drip irrigation systems to deliver water directly to the roots of crop plants, minimising evaporation and surface run-off

Drought-resistant Crops

Develop and cultivate crops that are resilient to drought conditions

These crops require less water to grow and are suited for arid regions

Switching to Vegetarian Food Production

Transition to plant-based agriculture to reduce the significant water usage associated with livestock farming

Case Study

Mitigation Strategies for Water Scarcity

Country Case Study: Australia

  • Some parts of Australia face water scarcity challenges due to the arid climate and variable rainfall

  • To address these issues, the country has implemented a range of innovative water management strategies, including:

  1. Water pricing mechanisms

    • Tiered water pricing: Australia uses a tiered pricing structure where the cost of water increases with higher usage levels

      • This approach incentivises households and businesses to conserve water

    • Water trading: in regions like the Murray-Darling Basin, water trading allows users to buy and sell water allocations

      • This market-based approach helps allocate water more efficiently, especially during drought periods

  2. Desalination plants

    • Sydney Desalination Plant: Sydney's only major source of non-rainfall dependent drinking water

      • This plant can supply up to 15% of Sydney's drinking water, providing a reliable water source during droughts

      • It uses reverse osmosis to remove salt and impurities from seawater, ensuring a continuous supply of fresh water

    • Perth Desalination Plant: one of the largest desalination plants in the Southern Hemisphere

      • It meets about half of Perth's water needs

      • This demonstrates the effectiveness of desalination in supplementing traditional water sources

  3. Water recycling programmes

    • Purple pipe systems: in some cities, recycled water is delivered through a separate "purple pipe" system for non-potable uses

      • This includes irrigation, industrial processes and toilet flushing

      • This reduces the demand on potable water supplies

    • Western Corridor Recycled Water Scheme: this project in Queensland treats and purifies wastewater to a standard suitable for industrial use

      • In times of need, it can also supplement drinking water supplies

  4. Crop selection and rotation

    • Drought-resistant crops: farmers are encouraged to grow crops like sorghum and millet

      • These require less water and are more resilient to dry conditions

      • Research institutions, such as the Commonwealth Scientific and Industrial Research Organisation (CSIRO), are developing new varieties of drought-tolerant crops

    • Sustainable farming practices: using crop rotation and conservation tillage helps maintain soil moisture and reduce water usage

      • For example, rotating legumes with cereals can improve soil fertility and reduce the amount of irrigation required

  5. Community awareness and education

    • Water conservation campaigns: public awareness campaigns, such as "Target 155" in Victoria, encourage residents to limit their water use to 155 litres per person per day

      • These campaigns educate the public on water-saving techniques and the importance of water conservation

    • School education programmes: schools incorporate water conservation into their curricula, teaching students about sustainable water use and the importance of preserving this vital resource

  • These strategies illustrate Australia's comprehensive approach to managing water scarcity through a combination of technological innovation, economic incentives and public education

Exam Tip

Although you do not need to learn this whole case study, you do need to be able to give a few named examples of how different countries or societies are using specific management strategies to address water scarcity.

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Alistair Marjot

Author: Alistair Marjot

Alistair graduated from Oxford University with a degree in Biological Sciences. He has taught GCSE/IGCSE Biology, as well as Biology and Environmental Systems & Societies for the International Baccalaureate Diploma Programme. While teaching in Oxford, Alistair completed his MA Education as Head of Department for Environmental Systems & Societies. Alistair has continued to pursue his interests in ecology and environmental science, recently gaining an MSc in Wildlife Biology & Conservation with Edinburgh Napier University.