Phrases For Different Global Water Issues, & What They Each Mean

The Different Phrases/Words Used To Describe Global Water Issues, & What They Mean

There are different phrases used to describe the different water issues in the world issues.

Different organisations or individuals may mean different things when they use them, and may use them in different contexts.

To clear up some of the uncertainty or confusion, what we’ve done in this guide is give a general definition of each phrase individually, and also relative to each other.

*Note – separate water issues outside of the scope of this guide are 1. Natural disasters involving water such as floods, and 2. Access to clean and safe drinking water, and basic sanitation and hygiene (a common issue to underdeveloped or developing regions)

 

Summary – Global Water Issue Phrases

Global water issues generally revolve around these key problems:

  • Quantity of water supplies (volume of available fresh water supplies, and the ratio of water being withdrawn and consumed vs the water resources being renewed)
  • Quality of water supplies (whether water meets the water standard/guidelines for an end use – for example, drinking water vs water used for irrigation) 
  • Access to water supplies (being able to extract, treat, transport and deliver water to it’s end use)

 

The different phrases used to describe different aspects of these problems are:

  • Water Availability – relates to quantity 
  • Water Access – relates to quantity 
  • Water Stress – relates to quantity 
  • Water Scarcity – relates to quantity 
  • Water Shortage – relates to quantity 
  • Water Pollution & Contamination – relates to quality, but also affects quantity 
  • The Water Crisis – relates to access, and quantity
  • Water Security – general phrase
  • Water Risk – general phrase

 

Water Availability

Water availability is the water available to withdraw or consume from a water supply resource in a particular region. This could be water from a catchment or river for example.

Water that is not available (at least not immediately with further technology or methods) is water such marine water, brackish water, frozen water, and some types of underground water.

Non available water can also include rainfall that doesn’t inflow into a usable water supply resource (because it evaporates, drains into a non usable water source, or is transpired by plants).

The mdba.gov.au resource has a good explanation of some of Australia’s water availability.

 

Water Access

Water access usually refers to basic access to safely managed and clean fresh water resources – which people can drink, or use for other uses such as household, industry or agricultural activities.

Water access is critical for both drinking water, and socio-economic development.

Water access usually has three main barriers:

  • Physical Water Access – only available water can be accessed. Some water can’t be accessed because of physical limitations such as being too isolated, or frozen
  • Economic Water Access – having the financial resources to invest in water infrastructure and systems to extract, treat, transport and deliver the water to the end user
  • Political/Institutional – inadequate political or institutional management of water access services and infrastructure 

Water access differs by region and country.

For example, a developing region may use simple water wells to extract drinking water from the ground, whilst a developed region may have full water treatment plants, pipes, taps, and so on.

 

Water Stress 

Water stress is a term used to describe the ratio of water demand (withdrawals) to water supply at any one time, and also, how much water resources may be remaining.

High water stress is an indicator that water demand and withdrawals might be outpacing renewal rates of a water supply source (a dam, a river, a ground water aquifer, and so on), and also that water supplies are usually trending towards being lower and lower.

Low water stress is an indicator that water supply renewal rates might be outpacing withdrawal/consumption rates, and that water supplies might be higher and not as much of a concern.

Countries with dry climates (low or variable rainfall), or that have low natural fresh water resources with growing populations and increasing demand might be in the highly water stressed country category.

Other descriptions of water stress are:

 

  • Water stress is the ratio of total withdrawals to total renewable supply in a given area. A higher percentage means more water users are competing for limited water supplies, and therefore that area/country is more stressed 

– wri.org

 

  • Compared to water scarcity, water stress is a more inclusive and broader concept. It considers several physical aspects related to water resources, including water scarcity, but also water quality, environmental flows, and the accessibility of water

– Pacinst

 

  • Water stress is defined based on the ratio of freshwater withdrawals to renewable freshwater resources.
  • Water stress does not insinuate that a country has water shortages, but does give an indication of how close it maybe be to exceeding a water basin’s renewable resources.
  • If water withdrawals exceed available resources (i.e. greater than 100 percent) then a country is either extracting beyond the rate at which aquifers can be replenished, or has very high levels of desalinisation water generation (the conversion of seawater to freshwater using osmosis processes)

– ourworldindata.org

 

The World Resources Institute (WRI) define baseline water stress based on the ratio of annual water withdrawals to renewable resources.

It defines water stress categories based on this percentage (% of withdrawals to renewable resources) as follows:

  • <10% = low stress
  • 10-20% = low-to-medium stress
  • 20-40% = medium-to-high stress
  • 40-80% = high stress
  • >80% = extremely high stress

– OurWorldInData/WRI

 

Wri.org defines a country using/withdrawing 80% or more of their total water supply as ‘highly water stressed’

Some of the countries projected to be most water stressed by 2040 are: Bahrain, Kuwait, Qatar, San Marino, Singapore, United Arab Emirates and Israel.

Read more about them at:

  • http://www.wri.org/blog/2015/08/ranking-world%E2%80%99s-most-water-stressed-countries-2040

 

Water Scarcity

Water scarcity is generally more extreme than water stress.

It could be described as ‘the lack of sufficient available water resources to meet the demands of water usage within a region’

At the point of water scarcity, the water demand (withdrawal) rate is usually exceeding the renewal rate of internal water resources, and the volume of available water at this point (usually around 20% of total capacity or lower) relative to demand is a concern. 

So, where water stress is a sliding scale (from low to extreme), water scarcity is a phrase used to describe the point where a population may be experiencing high or extreme water stress.

Similar to water access, water scarcity can be described as physical (lack of water, or over consumption of water) or economic (lack of financial investment or good governance) water scarcity.

There’s several ways to measure or assess water scarcity.

Pacinst has one example of a measurement of water scarcity compared to water stress:

  • If the amount of renewable water in a country is below 1,700 m3 per person per year, that country is said to be experiencing water stress; below 1,000 m3 it is said to be experiencing water scarcity; and below 500 m3, absolute water scarcity
  • [At levels between 1,700 and 1,000 cubic meters per person per year, periodic or limited water shortages can be expected]

Globalwaterforum.org also outlines some ways to measure or assess water scarcity:

1. Using the ‘Falkenmark indicator’ or ‘water stress index’ – measure scarcity as the amount of renewable freshwater that is available for each person each year [to a region or population of people, such as a city]. This indicator uses the same indicators that Pacinst outlines above

2. Criticality ratio – define water scarcity in terms of each country’s water demand compared to the amount of water available; measuring scarcity as the proportion of total annual water withdrawals relative to total available water resources. Using this approach, a country is said to be water scarce if annual withdrawals are between 20-40% of annual supply, and severely water scarce if they exceed 40%

3. International Water Management Institute (IWMI) Approach – assess scarcity by considering each country’s water infrastructure (such as desalination plants and recycled water) as well as internal fresh water sources (such as surface and ground water sources), and measuring it against consumptive water use rather than total withdrawals, whilst also considering the adaptive capacity of a country by assessing its potential for infrastructure development and efficiency improvements.

Using this approach, the IWMI classifies countries that are predicted to be unable to meet their future water demand without investment in water infrastructure and efficiency as economically water scarce; and countries predicted to be unable to meet their future demand, even with such investment, as physically water scarce.

4. Water Poverty Index – considers the role of income and wealth in determining water scarcity by measuring: (1) the level of access to water; (2) water quantity, quality, and variability; (3) water used for domestic, food, and productive purposes; (4) capacity for water management; and (5) environmental aspects. The complexity of this approach, however, means that it is more suited for analysis at a local scale, where data is more readily available, than on a national level.

 

Perth in Western Australia is an example of a city that experienced water scarcity, but has since addressed it with technology such as desalination and ground water replenishment (amongst other measures)

 

Water Shortage

Water scarcity and a shortage of water is often grouped as the same thing.

But, ‘water shortage’ is sometimes a phrase used to describe a specific type of water scarcity when clean fresh water supplies are getting to low enough levels where extreme water restrictions (say, level 7 or 8 water restrictions – sometimes called ‘Day Zero’) have to be enforced, and municipal tap water has to largely be turned off.

You can read a case study of the Cape Town water shortage in this guide.

Cape Town currently lives with stringent water restriction in terms of per capita per day allowances.

 

Water Pollution & Contamination

Water pollution and contamination initially impacts the quality of the water.

But, if water can’t be treated or purified, it also impacts quantity of water.

We’ve put together a full guide about water pollution and it’s causes, sources, effects plus solutions here.

 

Water Security

Water security is composed of two factors:

  • A population having an adequate quantity and quality of water for all their needs
  • That population and their water supplies being adequately protected from water related risks

 

Wikipedia.org defines water security as:

  • … the reliable availability of an acceptable quantity and quality of water for health, livelihoods and production, coupled with an acceptable level of water-related risks

 

Countries with high water stress, who are experiencing water scarcity or a water shortage, or who experience high levels of water contamination and pollution might be considered as having poor water security.

Countries with low water stress, high quantities of internal accessible fresh water resources, and have no foreseeable threat to the quantity or quality of their available water supplies in the future might be seen as having high water security.

 

Water Risk

Water Risk refers to the possibility [or probability] of an entity experiencing a water-related challenge (ceowatermandate.org)

A water related challenge can be a challenge like the ones listed above (e.g. water scarcity, water stress), but could also be other challenges like natural disasters affecting water supplies, water infrastructure leaking or being inadequate, and so on.

Pacinst has this to say on water risk:

  • Companies and organizations and governments cannot gain robust insight into water risk unless they have a firm understanding of the various components of water stress (i.e. water scarcity, accessibility, environmental flows, and water quality), as well as additional factors, such as water governance
  • Many water-related conditions, such as water scarcity, pollution, poor governance, inadequate infrastructure, climate change, and others, create water risk for many different sectors and organizations simultaneously

 

The Water Crisis

The ‘Water Crisis’ is the term used in two main ways:

1. To refer to the serious health crisis whereby people in mostly low income or underdeveloped regions lack access to basic water services such as clean and safe drinking water, and basic sanitation and hygiene. Nearly 1 million people die each year from water, sanitation and hygiene-related diseases which could be reduced with access to safe water or sanitation. Every 2 minutes a child dies from a water-related disease. Over one billion people in developing countries have inadequate access to clean water.

The significant challenge in many of the regions affected is low income, and/or poor institutional governance/management.

Read more in these guides:

  • https://www.worldvision.com.au/global-water-crisis-facts
  • https://water.org/our-impact/water-crisis/

 

2. To refer to other water issues getting worse in the future, whereby an increasing number of even developed countries are heading towards higher rates of water stress unless they address these issues (much like Perth in Western Australia has done) – and, this of course has the potential for worsening consequences.

 

 

Sources

1. https://pacinst.org/water-definitions/

2. Hannah Ritchie and Max Roser (2018) – “Water Access, Resources & Sanitation”. Published online at OurWorldInData.org. Retrieved from: ‘https://ourworldindata.org/water-access-resources-sanitation’ [Online Resource]

3. https://en.wikipedia.org/wiki/Water_issues_in_developing_countries#Challenges_to_Water_Quality

4. https://www.lenntech.com/water-pollution-faq.htm

5. http://www.unwater.org/publications/water-security-infographic/

6. http://www.wri.org/blog/2015/08/ranking-world%E2%80%99s-most-water-stressed-countries-2040

7. http://www.wri.org/blog/2013/12/world%E2%80%99s-36-most-water-stressed-countries

8. https://ceowatermandate.org/posts/water-scarcity-water-stress-water-risk-actually-mean/

9. https://water.org/our-impact/water-crisis/

10. https://water.org/our-impact/

11. https://www.mdba.gov.au/education/resources/water-availability#

12. https://en.wikipedia.org/wiki/Water_security

13. https://www.worldvision.com.au/global-water-crisis-facts

14. http://www.globalwaterforum.org/2012/05/07/understanding-water-scarcity-definitions-and-measurements/

15. https://en.wikipedia.org/wiki/Economic_water_scarcity

16. https://en.wikipedia.org/wiki/Physical_water_scarcity

17. https://en.wikipedia.org/wiki/Water_scarcity

How Much Land Is There On Earth, & What Is It Used For?

How Much Land Is There On Earth? - Total, Inhabitable, Arable, Agricultural & Cultivated

This is a guide about how much land there is on earth.

Below we’ve outlined some of the more important land quantity and land usage stats such as total land, habitable land, agricultural land and arable land.

We’ve also noted what arable land is used for, and countries that have the most cultivated land in total.

Note that these numbers are estimates, and are to be used as a general guide only.

 

Summary – How Much Land Is There On Earth?

  • About 29% of the total surface of the earth is land (the rest is water)
  • Of that, there is habitable land (that we can live on) and non habitable land, and agricultural (including land that livestock can be farmed on) and arable land (more fertile land with topsoil for growing crops)
  • About 37% of the Earth’s land surface is agricultural land, and 11% arable
  • Most of the agricultural land we use is used for livestock (about 77%), and a much smaller % is used for crops (about 23%)
  • Surprisingly though, most of the World’s caloric consumption supply comes from plant based food, and most of the protein consumption supply comes from plant based food (as opposed to dairy and meat)
  • There is still some farmable land left on Earth, but there could be access and practical farming challenges involved in using some of it it

 

How Much Land Is There On Earth/In The World In Total?

  • Of the land’s total surface, about 29% of that surface is land, and 71% is ocean

The quantities that make up those %’s are:

  • Land – 149 million km², or 92.5 million mi.²
  • Ocean – 361 million km², or 224.3 million mi.²

– OurWorldInData/FAO

You can read more about the how much water there is on earth in this guide.

 

How Much Habitable Land Is There On Earth?

About 71% of the total land surface on earth is habitable, with the rest being glaciers (10%) and barren land (19%).

The quantities that make up those %’s are:

  • Habitable Land – 104 million km², or 64.6 million mi.²
  • Glaciers – 15 million km², or 9.32 million mi.²
  • Barren Land – 28 million km², 17.3 million mi.²

– OurWorldInData/FAO

 

How Much Agricultural/Farmable Land Is There On Earth?

Agricultural land includes arable land for crops, but also land that can be used for rearing livestock.

 

  • According to World Bank data, in 2015, approximately 37% of the world’s land surface was agricultural land.

– data.worldbank.org

 

  • Roughly between 32 and 36 million square kilometers (12 and 14 million square miles) of land is used to raise livestock

– Sciencing/University of Wisconsin-Madison

 

How Much Arable Land Is There On Earth?

Arable land just includes land that can be used for growing crops, and not livestock rearing land.

 

  • According to World Bank data, in 2015, approximately almost 11% of the world’s land surface was arable land.

– data.worldbank.org

 

  • Approximately 17.6 million square kilometers (6.8 million square miles) of land is used to grow crops

– Sciencing/University of Wisconsin-Madison

 

What Is The World’s Habitable Land Used For?

  • About 50% of the world’s habitable land is used for agriculture, 37% for forests, 11% for shrubland, 1% for urban development, and 1% is freshwater

– OurWorldInData/FAO

 

The quantities that make up those %’s are:

  • Agriculture – 51 million km², or 31.6 million mi.²
  • Forests – 39 million km², or 24.2 million mi.²
  • Shrubs – 12 million km², or 7.4 million mi.²
  • Urban – 1.5 million km², or 0.93 million mi.²
  • Freshwater – 1.5 million km², or 0.93 million mi.²

 

What Is The World’s Agricultural Land Used For?

  • Of the world’s land that is used for agriculture, about 77% is used for livestock rearing/meat and dairy production, and 23% is used for growing crops.

– OurWorldInData/FAO

 

The quantities that make up those %’s are:

  • Livestock – 40 million km², or 24.8 million mi.²
  • Crops – 11 million km², or 6.83 million mi.²

Even with the above numbers, it’s interesting to note that 83% of the world’s caloric consumption supply comes from plant based food, whilst only 17% comes from meat and dairy production. 

Likewise, about 67% of the world’s protein consumption supply comes from plant based food, whilst only 33% comes from meat and dairy. 

– OurWorldInData/FAO

 

  • Current estimates (as of 2017) put the remaining amount of farmable land at about 27 million square kilometers (10.5 million square miles), most of which is concentrated in Africa and Central and South America. 

– Sciencing

 

Of course, population growth significantly affects how much land we can or are using for agriculture at any one time.

 

What Is The World’s Arable Land Used For?

You can view a list of the world’s most valuable crops, and crop production by metric tonnes here – https://en.wikipedia.org/wiki/List_of_most_valuable_crops_and_livestock_products

 

In order, some of the top value producing crops are (not including meat and dairy):

  1. Rice, paddy
  2. Wheat
  3. Soybean
  4. Tomatoes
  5. Sugarcane
  6. Maize (corn)
  7. Potatoes
  8. Vegetables (not listed elsewhere)
  9. Grapes
  10. Cotton
  11. Apples
  12. Bananas
  13. Cassava (yuca)
  14. Mangos, Mangosteens, Guava
  15. Coffee
  16. Palm Oil
  17. Onion, dry
  18. Beans, dry and green
  19. Peanuts
  20. Olives

– Wikipedia/FAO

 

What Do Different Countries Use Their Cultivated Land For?

You can view a list of land use statistics by country here – https://en.wikipedia.org/wiki/Land_use_statistics_by_country 

 

In order, the countries with the most total cultivated land area are:

  1. India
  2. United States
  3. China
  4. Russia
  5. Brazil
  6. Canada
  7. Australia
  8. Indonesia
  9. Nigeria
  10. Argentina
  11. Ukraine
  12. Sudan
  13. Mexico
  14. Kazakhstan
  15. Turkey
  16. Pakistan
  17. France
  18. Thailand
  19. Iran
  20. Ethiopia

– Wikipedia/CIA World Factbook

 

Will We Have Enough Agricultural Land To Grow Food In The Future?

Read more in this guide about the future availability and capacity of agricultural land to grow/produce food into the future.

 

Sources

1. https://ourworldindata.org/agricultural-land-by-global-diets ( by Hannah Ritchie)

2. https://data.worldbank.org/

3. https://sciencing.com/much-earths-land-farmable-16685.html

4. https://en.wikipedia.org/wiki/List_of_most_valuable_crops_and_livestock_products

5. https://en.wikipedia.org/wiki/Land_use_statistics_by_country

6. https://data.worldbank.org/indicator/AG.LND.AGRI.ZS

7. https://data.worldbank.org/indicator/AG.LND.ARBL.ZS?view=chart 

8. https://www.bettermeetsreality.com/how-much-land-in-the-world-is-used-for-agriculture-do-we-have-enough-arable-agricultural-land-left-for-food-other-resources-in-the-future/

How Much Water Is There On Earth? (Ocean Water, Fresh Water & Drinkable Water)

How Much Water Is There On Earth? - Ocean, Fresh Water & Drinkable Water

A large portion of the Earth’s water is in the ocean.

Fresh water is distributed unequally in much smaller amounts amongst different countries. 

Not all fresh water is drinkable though.

In this guide, we outline the the % share of each water type on Earth.

*Note – these numbers are estimates, and are to be used as a general guide only. Also, these number take into consideration the Earth’s surface only. There is also water in the Earth’s atmosphere, in clouds, as water vapour (some estimates put water vapour at 0.001% of the Earth’s water share/distribution), and even in plants and other life.

 

Summary – How Much Water Is There On Earth?

The water on earth can be divided into:

  • About 71% of the world’s surface is covered by water
  • Roughly 96.5% of water on the Earth’s surface is in the ocean
  • Roughly 2-3% of water is freshwater, and about 1.6% of that is locked up in ice and now
  • 0.36% of freshwater is found underground in aquifers and wells (groundwater)
  • Only about 0.036% of the planet’s total water supply is found in lakes and rivers (surface water)
  • Not all fresh water is accessible for different reasons, and not all fresh water that is accessible is immediately drinkable (due to factors like being being brackish water, or being contaminated) 
  • Less than 1 percent of the world’s total freshwater supply is readily accessible from the various freshwater sources
  • The % of water available on earth that is ready and available to drink and use, tworks out to be about 0.007%
  • This number only represents natural water sources though, and not technology such as desalination that can augment water supplies. Perth in Western Australia is an example of a city currently using desalination technology to augment their water supply
  • Read more in this guide specifically about fresh water supplies around the world

 

How Much Of The Earth’s Surface Is Water?

  • About 71% of the world’s surface is covered by water

– water.usgs.gov

 

If water quantities were to be described in spheres, the water distributions are as follows:

  • A sphere of all water on Earth would have a diameter of about 860 miles
  • A sphere of all of Earth’s fresh water would have a diameter of about 169.5 miles 
  • A sphere of all of Earth’s immediately accessible fresh water would have a diameter of 34.9 miles 

– water.usgs.gov

 

How Much Water Is In The Ocean?

  • Of the world’s surface water, about 96.5% is the ocean

– water.usgs.gov

 

  • The average depth of the ocean is several thousand feet (about 1000 metres)

– science.howstuffworks.com

 

This gives us a rough idea of the volume of saltwater on earth.

 

How Much Fresh Water Is There On Earth?

  • About 2-3% percent of the planet’s water is fresh, but 1.6 percent (around 70%) of the planet’s fresh water is locked up in the polar ice caps, snowfields and glaciers
  • 0.36 percent of freshwater is found underground in aquifers and wells (also called groundwater)
  • Only about 0.036 percent of the planet’s total water supply is found in lakes and rivers 

– science.howstuffworks.com

 

Explained another way:

  • 3% of the world’s water is fresh water
  • 69% of the 3% is in glaciers and ice caps
  • 30% of that 3% is in ground water in underground soil and rock crevices
  • 1% of that 3% is in surface water and other sources
  • Of that surface water, 87% is in lakes, 11% in swamps and 2% in rivers

– the71percent.org

The full resource is worth reading as they list some of the places on Earth that hold the highest concentrations (in volume) of fresh water – https://www.the71percent.org/the-worlds-fresh-water-sources/

 

The rest of the water on the planet is either floating in the air as clouds and water vapor, or is locked up in plants and animals and living things like humans

There’s also billions of gallons of drinkable water in bottles of water in shops on shelves around the world at any one time.

It’s important to note water is constantly moving on the Earth between the atmosphere, ocean, rivers and streams, snowpacks and ice sheets, and underground. This is known as the hydrologic cycle.

 

Read more about fresh water resources and supplies, how we use them, and what to consider when managing fresh water into the future in this guide.

 

How Much Drinkable Water Is On Earth?

  • Less than 1 percent of the world’s total freshwater supply is readily accessible from the various freshwater sources

– livescience.com

 

  • That’s still thousands of trillions of gallons, but it’s a very small amount compared to all the water available
  • As a % of the total amount of water available on earth that is ready and available to drink and use, that % number works out to be about 0.007 percent

– nationalgeographic.com

 

In other words, when you subtract all the salt water, water trapped in ice/snow and water not physically accessible, you have about 0.007% left to drink, and use for business, agriculture and the community.

Much of that water we get from rivers and lakes – but each country in the world and even different cities withdraw and consume different shares of water from surface water and ground water sources. 

Some of it is not going to be drinking quality – because of water pollution or contaminants, or even because it’s brackish water (too saline).

Some water can be treated or purified to drink (after it’s been tested) at water treatment plants, but some can’t.

Water used for agriculture and irrigation may not have to reach the same quality standards as drinking water.

Cities now are even using water from water recycling and water desalination (which are not included in the above estimates and numbers as these are not natural sources of water).

 

Detailed Look At Where Water On Earth Is Located/Distributed By Source

You can look at a detailed table showing global water distribution at

  • https://water.usgs.gov/edu/earthhowmuch.html    
  • https://water.usgs.gov/edu/gallery/global-water-volume.html 

 

Mdba.gov.au also outlines the following % distributions of Earth’s water:

  • Water Vapour – 0.001%
  • Fresh Water (on the surface – lakes, rivers, etc) – 0.025%
  • Fresh Water (underground) – 0.615%
  • Fresh Water (frozen in ice caps, glaciers, snow) – 2.15%
  • Salt Water (underground) – 0.93%
  • Salt Water (oceans) – 97.2%

 

Countries With The Most Freshwater

  • 6 countries (Brazil, Russia, Canada, Indonesia, China and Colombia) have 50 percent of the world’s freshwater reserves
  • One-third of the world’s population lives in “water-stressed” countries, defined as a country’s ratio of water consumption to water availability. Countries labeled as moderate to high stress consume 20 percent more water than their available supply.

– livescience.com

 

  • Due to geography, climate, engineering, regulation, and competition for resources, some regions seem relatively flush with freshwater, while others face drought and debilitating pollution.
  • In much of the developing world, clean water is either hard to come by or a commodity that requires laborious work or significant currency to obtain

– nationalgeographic.com

 

Will We Have Enough Water In The Future For Human Use?

Read this guide about the availability of freshwater for humans in the future.

 

Sources

1. https://water.usgs.gov/edu/earthhowmuch.html

2. https://science.howstuffworks.com/environmental/earth/geophysics/question157.htm

3. https://www.livescience.com/29673-how-much-water-on-earth.html

4. https://www.nationalgeographic.com/environment/freshwater/freshwater-crisis/

5. https://water.usgs.gov/edu/gallery/global-water-volume.html

6. https://www.bettermeetsreality.com/freshwater-supply-usage-around-the-world-how-much-freshwater-we-have-how-much-we-use-how-we-use-it/

7. https://www.mdba.gov.au/education/resources/water-availability#

8. https://www.the71percent.org/the-worlds-fresh-water-sources/