The supply of fresh water supply varies globally — Edexcel GCSE Geography A
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The supply of fresh water supply varies globally explained
The supply of fresh water supply varies globally covers 4 specification points, including a.
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Global distribution of fresh water. and B. How the availability of fresh water varies…. Open a point below for its explanation and revision guidance.
a. Global distribution of fresh water.
Fresh water is only about 2.5 per cent of Earth's water, and much of that is locked in ice caps, glaciers and deep groundwater. Global distribution asks where fresh water is found and how unevenly it is spread. Learners should describe broad patterns on a world map, contrasting regions with high rainfall and large rivers against arid or semi-arid regions with little surface water. In a multiple-choice question, check each option against the idea of distribution: the correct option usually names a location, a source such as lakes or aquifers, or a clear regional contrast, not a general statement that water exists.
b. How the availability of fresh water varies on a global, national and local scale.
Fresh water availability changes with the scale examined, so learners must identify which scale a question describes. At a global scale, the focus is on differences between continents and major world regions. At a national scale, compare countries, or differences within a large country, such as wetter and drier areas. At a local scale, consider a single town, valley or aquifer and what supplies it, such as a reservoir, river or groundwater. A strong answer uses a concrete example at the stated scale and explains why availability differs, for example through rainfall, geology or demand. Identify the scale in the question stem before choosing an option in a multiple-choice question.
c. Why some parts of the world have a water surplus or a water deficit.
This statement asks why some regions have a water surplus and others a water deficit. A surplus means supply exceeds demand; a deficit means demand is greater than the supply that can be reliably accessed. Climate is the main natural control: humid tropical and high-latitude areas, with high precipitation and low evaporation, often have a surplus, while hot, dry subtropical interiors often have a deficit. Geology and relief matter because permeable rock stores groundwater and steep slopes shed water quickly. Human factors such as population density and irrigated farming can turn a surplus into a deficit when demand rises. Use one named example and a clear cause-and-effect chain.
d. How and why the supply and demand for water has changed in the past 50 years due to human intervention.
This statement asks how and why fresh water supply and demand have changed over the past 50 years because of human intervention. Keep examples within that period. How describes the direction of change, such as demand rising with population and irrigated farming, or supply altered by dams and groundwater pumping. Why names the human action responsible, such as reservoirs storing river water, boreholes abstracting groundwater, or waste reducing usable supply. Desalination increases supply but uses energy and money.
Your focus
- State the approximate proportion of Earth's water that is fresh.
- Describe the uneven global pattern of fresh water using named regions.
- Select the multiple-choice option that correctly describes the global distribution of fresh water.
Show all 12 objectives
- Identify whether a description refers to the global, national or local scale.
- Give a named example of variation in fresh water availability at a chosen scale.
- Explain one cause of differing fresh water availability.
- Define water surplus and water deficit using supply and demand.
- Explain two natural controls on water availability.
- Apply one named example to explain why a region has a surplus or a deficit.
- Identify two human interventions that have changed water supply in the past 50 years.
- Describe one change in water demand and its human cause.
- Explain how one intervention alters the balance between supply and demand.
The supply of fresh water supply varies globally exam tips
Marking Points
- Identifies fresh water as a very small proportion of Earth's total water.
- Describes the uneven spatial pattern of fresh water across continents and regions.
- Links areas of abundant fresh water to high rainfall or large river systems, such as the Amazon basin.
- Recognises that much fresh water is stored as ice or groundwater and is not easily accessible.
- Uses named locations or map evidence to support the pattern described.
- Specifies whether the answer addresses the global, national or local scale.
- Compares fresh water availability between world regions at the global scale.
- Explains national differences, such as wetter and drier areas within a country, using a named example.
- Describes local sources of supply, such as a reservoir, river or aquifer, at the local scale.
- Explains a cause of variation, such as rainfall, geology or demand, and links it to how much water is accessible.
- Identifies a surplus as supply exceeding demand and a deficit as demand exceeding reliable supply.
- Explains that precipitation exceeding evaporation and runoff creates a surplus in humid regions.
- Links hot, dry subtropical interiors to low precipitation and high evaporation, producing a deficit.
- Explains how permeable geology stores groundwater whereas steep relief lets water drain away quickly.
- Explains how rising demand from population growth or irrigation can create a deficit where supply is limited.
- Applies a named example accurately to a surplus or deficit region.
- Describes how demand changed over the past 50 years, such as rising household, farming and industrial use with population growth.
- Describes how supply changed, such as new reservoirs or boreholes increasing the amount of water available.
- Explains why each change occurred by naming a specific human intervention.
- Links a named human action to its effect on supply or demand within the 50-year period.
- Recognises that pollution or over-abstraction can reduce usable supply.
Examiner Tips
- 💡Read every multiple-choice option and reject any that describe a process rather than a location or pattern.
- 💡In a written answer, name a specific region or water source such as lakes, rivers or aquifers.
- 💡Use distribution language in your answer, stating where water is found, how much is available and how unevenly it is spread.
- 💡Underline the scale word in the question stem before answering, whether it is global, national or local.
- 💡When several scales are required, give one named example for each scale.
- 💡Explain the cause of variation as well as describing the pattern.
- 💡Read the stem to check whether it asks about supply, demand or the balance between them before choosing an option.
- 💡Eliminate options that describe only one factor when the question concerns the balance of supply and demand.
- 💡Check each option against the definitions of surplus and deficit before selecting your answer.
- 💡Check that each example you select falls within the past 50 years before choosing your answer.
- 💡Structure your reasoning as what changed followed by why it changed.
- 💡Make sure the selected option addresses both supply and demand.
Common Mistakes
- Treats all water on Earth as fresh water; distinguish saline sea water from fresh water before describing distribution.
- Confuses distribution with the water cycle by describing evaporation or precipitation rather than where water is located.
- Describes fresh water as evenly spread across the world; state the regional contrasts instead.
- Uses a national statistic to describe a local situation; keep each example at the scale named in the question.
- Describes only one scale when the question asks how availability varies across all three; cover each scale named.
- Gives a cause of variation without linking it to availability; state how the factor changes how much water people can use.
- Describes a deficit as a lack of rainfall alone; correct by also considering demand and access to stored water.
- Assumes every dry place has a deficit; correct by checking whether demand is greater than the reliable supply.
- Lists places with surplus or deficit without explaining the cause; correct by linking each place to a named factor.
- Gives natural causes such as drought as the main reason; correct by focusing on the human intervention the question requires.
- Writes about changes before the 50-year period; correct by restricting examples to the past 50 years.
- Describes only supply or only demand; correct by covering both and how they relate.
- Describes a change without explaining its human cause; correct by naming the intervention responsible.