CIE IGCSE Geography – Water
1. Key Definition: Water Supply
Water supply refers to the sources, storage, treatment and distribution of water for human use.
Water is essential for:
- Drinking and sanitation
- Agriculture
- Industry
- Energy production
- Economic development
Without a reliable water supply, health, agriculture, and economic growth are severely affected.
2. Main Uses of Water
Water is mainly used for three sectors:
| Use | Description | Examples |
|---|---|---|
| Agriculture | Irrigation of crops and watering livestock | Rice farming, wheat farming |
| Domestic | Household uses | Drinking, washing, cooking |
| Industrial | Factories and energy production | Cooling machinery, manufacturing |
Global Distribution of Water Use
Approximate global proportions:
| Sector | Percentage of global water use |
|---|---|
| Agriculture | ~70% |
| Industry | ~20% |
| Domestic | ~10% |
However, this varies depending on level of economic development.
Water Use in Countries at Different Levels of Development
High-income countries
Example: United States
Characteristics:
- High industrial water use
- Advanced irrigation systems
- High domestic consumption
Typical pattern:
| Sector | Approximate use |
|---|---|
| Agriculture | 40–50% |
| Industry | 40% |
| Domestic | 10–20% |
Reasons:
- Large manufacturing industries
- High living standards
- Water-intensive lifestyles
Low-income countries
Example: Ethiopia
Characteristics:
- Agriculture dominates water use
- Limited industry
- Lower domestic consumption
Typical pattern:
| Sector | Approximate use |
|---|---|
| Agriculture | 80–90% |
| Industry | <5% |
| Domestic | 10% |
Reasons:
- Economies rely heavily on farming
- Less industrial activity
- Limited water infrastructure
3. Methods of Water Supply
Different regions use different methods depending on climate, geology, technology, and wealth.
3.1 Reservoirs and Dams
Definition
A reservoir is a large artificial lake created by building a dam across a river to store water.
Stored water can be used for:
- Drinking water
- Irrigation
- Hydroelectric power
- Flood control
Example:
- Three Gorges Dam
- Aswan High Dam
Advantages
- Large and reliable water supply
- Provides water during dry seasons
- Can generate hydroelectric power
Disadvantages
- Very expensive
- Flooding of land and habitats
- People may need to relocate
- Environmental impacts
3.2 Wells and Boreholes
Definition
A well is a hole dug into the ground to reach groundwater.
A borehole is a deeper, narrow hole drilled using machinery.
Water comes from aquifers (underground water-bearing rocks).
Common in rural areas.
Example:
- Boreholes widely used in rural areas of Kenya.
Advantages
- Relatively cheap
- Good for rural communities
- Access to underground water during droughts
Disadvantages
- Can run dry if overused
- Water may be contaminated
- Requires pumps and maintenance
3.3 Desalination
Definition
Desalination is the process of removing salt from seawater to produce fresh water.
Common in dry coastal countries.
Example:
- Saudi Arabia uses many desalination plants.
Advantages
- Provides water in desert regions
- Reliable supply near oceans
Disadvantages
- Very expensive
- Uses large amounts of energy
- Produces salty waste that may harm marine ecosystems
4. Causes of Water Shortages
Water shortages occur when water demand exceeds available supply.
4.1 Climate Factors
Low rainfall
Dry climates receive little precipitation.
Example:
- Sahara Desert region.
Drought
Long periods without rain reduce river and groundwater levels.
4.2 Population Growth
Rapid population growth increases water demand.
Example:
- Cities like Lagos have rapidly growing populations needing more water.
4.3 Agriculture
Irrigation uses huge amounts of water.
Example:
- Large irrigation projects near the Nile River.
4.4 Industrialisation
Factories require large quantities of water for:
- Cooling
- Processing materials
- Manufacturing
4.5 Pollution
Water supplies become unusable when contaminated by:
- Industrial waste
- Agricultural chemicals
- Sewage
Example:
- Pollution problems in rivers in India.
4.6 Poor Infrastructure
Some countries lack:
- Pipelines
- Water treatment plants
- Storage facilities
As a result, people may rely on unsafe water sources.
5. Impacts of Lack of Clean Water
Lack of access to clean water has serious social and economic impacts.
5.1 Health Problems
Dirty water spreads diseases such as:
- Cholera
- Typhoid
- Dysentery
This leads to:
- High death rates
- Poor health
- Increased medical costs
5.2 Time Spent Collecting Water
In many rural areas, people (often women and children) walk long distances to collect water.
Impacts:
- Less time for school
- Reduced productivity
- Physical strain
5.3 Reduced Agricultural Productivity
Without irrigation:
- Crops fail
- Food shortages occur
- Farmers lose income
5.4 Slower Economic Development
Water shortages can limit:
- Industrial growth
- Tourism
- Investment
Countries struggle to develop economically.
6. Water Management
Careful management ensures sustainable water supply for the future.
6.1 Conservation
Reducing water waste through:
- Efficient irrigation
- Fixing leaks
- Water-saving appliances
6.2 Recycling Water
Treating wastewater so it can be reused for:
- Agriculture
- Industry
6.3 Rainwater Harvesting
Collecting rainwater from roofs and storing it in tanks.
Common in rural communities.
6.4 Government Planning
Governments may:
- Build dams
- Improve water treatment systems
- Introduce water pricing policies
7. Case Study: Water Supply in Singapore
Country: Singapore
Singapore has limited natural freshwater resources and relies on several methods to secure water.
Sources of Water
- Local rainfall collected in reservoirs
- Imported water from Malaysia
- Desalination plants
- Recycled water (NEWater)
Example: Desalination and Water Recycling
Singapore developed advanced technologies to produce clean water from seawater and wastewater.
Benefits:
- Reliable supply despite limited natural resources
- Supports industry and population growth
- Reduces dependence on imported water
Challenges:
- High cost
- High energy use
8. Exam Tips for Water Questions
Tip 1: Use specific examples
Instead of writing:
❌ "Some countries have desalination."
Write:
✅ "Countries such as Saudi Arabia use desalination to produce freshwater from seawater."
Tip 2: Explain your points
Example:
Poor answer:
Water shortages occur due to population growth.
Better answer:
Rapid population growth increases water demand for drinking, sanitation and agriculture, which can exceed available supplies.
Tip 3: Structure 6-mark questions
Use PEE structure:
Point
Explanation
Example
9. Important Terms to Memorize
Water scarcity
When water demand exceeds available supply.
Aquifer
Underground rock layer that stores water.
Desalination
Removal of salt from seawater.
Reservoir
Artificial lake used to store water.
Irrigation
Artificial watering of crops.
10. Key Summary
You should remember:
✔ Main water uses (agriculture, domestic, industrial)
✔ Methods of water supply (reservoirs, wells, desalination)
✔ Causes of water shortages
✔ Impacts of lack of clean water
✔ Water management strategies
✔ A detailed case study