Imagine there isn't enough water for you and your family and friends. Now, imagine that there is enough water but it's dirty and cleaning it is too expensive. Water scarcity is a problem for millions of people across the world. Some scientists think it could be a problem for around 5 billion of us by 2050. Could that include you? What can we do to stop it? Let's find out.
Water scarcity definition
Have you ever heard of the water budget? The water budget is the first thing we need to understand when learning about water scarcity. The water budget is a way of measuring how much water there is in a system, by comparing how much water is coming in with how much water is going out. If more water is coming into a system than is leaving, we call it a water surplus. Generally, this is not a bad thing unless the imbalance is so extreme that it causes flooding. If, however, more water is leaving a system than coming in, we have a water deficit. What does this mean? Depending on how severe the water deficit is, this can lead to drought and water shortages. When water shortages get extreme, we call it water scarcity - something that happens where this is enough water to meet population demands.
Water scarcity happens when there is not enough water to meet the demands of the population.
But is water scarcity the same everywhere? No - of course it isn't! We can divide water scarcity into two main types: physical and economic. Let's take a look at what they both mean.
Physical water scarcity
Physical water scarcity is when there is not enough water to meet population demands simply because there is not enough water present. We will talk more about why this happens later on, but here's a clue - it relates to the concept of the water budget that we mentioned earlier. This type of water scarcity can be found all over the world, but it is particularly common in arid areas.
If a place is described as 'arid', it significantly lacks water. Deserts are arid landscapes.
Economic water scarcity
Economic water scarcity occurs when there is not enough water to meet population demands because of things related to money. Water might cost too much for people to afford and/or cleaning dirty water to use might be too expensive. This way, although there is water present (unlike with physical water scarcity), it is unsafe to use. Economic water scarcity can typically be found in lower-income countries (LICs), as these are the countries that usually can't afford infrastructure that can provide regularly available clean water.
Causes of water scarcity
If there were just one cause of water scarcity it would be a lot easier for us to handle. Why? Because we could come up with a solution that could be used across the world. As you've probably guessed, it isn't that easy. This is, in part, because there are many potential causes of water scarcity.
As we go on to explain the causes, try to think if they are a physical cause or an economic cause of water scarcity. Making this distinction in your exam could help you get higher marks!
Let's go through a few common causes of water scarcity: over-abstraction, pollution, dam construction and climate change.
Over-abstraction
To understand what over-abstraction is, it makes sense that we start by talking about what abstraction is. Water abstraction is just a fancy name for taking water out of a water store like a river or a lake or even a groundwater source. So, if abstraction is removing water from a store, over-abstraction is removing too much water from a store. This can often mean that water is completely removed from a store, and sometimes this stops the store from storing water again.
Groundwater is the water that is stored under the ground in the spaces between rocks and the soil. This is a useful store of water, from which water can be extracted for use.
Remember when we mentioned the water budget and how it refers to the balance between the inputs and outputs of water in a system? Over-abstraction is an example of a human-induced water deficit, where the output of water is greater than the inputs of water, whether that's via precipitation or artificial human inputs. This, unsurprisingly, results in decreasing water levels and physical water scarcity.
But why does over-abstraction happen? The answer is people. Humans need water for many reasons including to drink and in industries like agriculture. As the number of humans on Earth increases, so does the demand for water. That means that more water needs to be extracted from stores, which can lead to over-abstraction.
Pollution
Pollution doesn't just happen from car emissions contaminating the air, it can also be present in water. Untreated sewage, fertilisers and oil spills can contaminate water stores, just as acid rain can. In fact, there are many potential causes of water pollution. What type of water scarcity can this cause? If you thought economic water scarcity - then you were right. When water is polluted, for whatever reason, it can be unsafe for use. Unless there is money available to treat the water and make it safe, it cannot be used. This can contribute to water scarcity.
Dam construction
Dams act as barriers that stop the flow of water. Stopping water flow can create what we call a reservoir, which is essentially a large store of water. You might be thinking that this seems like a clever way to combat water scarcity. It can be, but only for some people. Let's think about this with a hypothetical example:
Imagine that there is a river that runs through 2 countries (Country A and Country B). Both countries use water from the river to sustain their populations and keep their industries running. Country A decides to build a dam so that it can access more water and meet the needs of its people. This works wonders and the people in Country A have plenty of water. But what about Country B? By stopping the flow of the river into Country B, Country A has created a water deficit and water scarcity by extension.
This may seem unfair to you. Surely a country wouldn't actually deprive another country of something as essential as water? Wrong! There are many examples of this happening in real life and thousands of people have been impacted as a result.
The Grand Renaissance dam was opened in Ethiopia in 2020, after 9 years of construction. The dam is located on the Blue Nile River, a river which usually ran through Ethiopia and Sudan but also feeding into lots of other rivers supplying water to countries like Egypt. The creation of the dam has created lots of tension between Ethiopia and other countries benefitting from the river. They worry that the dam will reduce the water available to them and create physical water scarcity.
Fig. 2 - A map of the Grand Renaissance dam in Ethiopia
Climate change
Climate change is one of the biggest environmental problems of our time. You have probably heard a lot about the ice caps melting, temperatures rising and animals going extinct, but did you know that climate change affects water security too? There are a few ways that this can happen:
- Droughts
- Sea level rise
- Acid rain
Let's take a look at these in a bit more depth.
Droughts
A drought is a period of time where there are unusually low levels of rain. This can create physical water scarcity by disrupting the water budget and reducing the amount of water going into a system. Droughts can have terrible and long-lasting effects on people, from crop failure to people dying from a lack of water. Climate change is expected to increase the risk of droughts through increasing evaporation with higher temperatures and by altering rainfall regimes. As well as simply increasing the frequency of droughts, scientists estimate that climate change will also increase how long droughts last. This means that periods of physical water scarcity will last longer in many places, making them more difficult to manage.
Sea level rise
Sea level rise will continue as global temperatures continue to rise and ice melts across the world. This could lead to flooding and entire countries (e.g. Kiribati and Tuvalu) being submerged under the water. How does this flooding impact water security? If sea levels were to rise and flood freshwater sources, the water would become salinated. In the same way that seawater is not safe to drink, neither would the freshwater source after contamination. And what could happen if there was not the money or infrastructure available to treat this water? You guessed it - economic water scarcity.
Acid rain
You have probably come across the term 'acid rain' before, but what is it? Some types of pollution, like sulfur dioxide (SO2), can cause rain to become more acidic than 'normal'. When this rain falls into water stores, it can make the water more acidic overall. If this happens with enough frequency, the water could become unsafe for use without treatment. As we know, not everybody has access to the resources needed to decontaminate water. This can contribute to economic water scarcity.
Impacts of water scarcity
Now that we know what water scarcity is and why it happens, it's time to think about what impacts this has on people and the environment that they find themselves in.
Fig. 3 - Water scarcity can result in people walking long distances for unsafe drinking water
In Geography, it is useful to divide your effects into social, economic and environmental effects. Unless a question specifies otherwise, it is good to use a combination of these types of effects in exam answers.
Social effects | Economic effects | Environmental effects |
| Water scarcity can mean that people have to travel further to get water. This takes more time, is inconvenient and for some is simply not possible. Alternatively, people may be drinking unsafe water, which can lead to diseases like typhoid and cholera. | Not having enough water within a country could mean that people have to rely on buying water from other countries and having it imported. To create the pipelines to allow this (and to afford the water itself) a lot of money needs to be spent, which can be difficult for some countries. | Water pollution, a cause of economic water scarcity, has several environmental effects. It can alter the habitat of many species to a point where they are no longer able to survive. This can lead to a decline in biodiversity. |
| Not having enough water can result in serious illnesses from severe dehydration and can eventually result in death. As well as the obvious social implications of this, more illnesses and deaths can strain healthcare services. | If there is not enough water to feed crops, then crops will die. As many countries rely on agriculture to earn money, a lack of crops can cause financial difficulty and economic decline. | Treating water that is unsafe for use can use a lot of energy. Using non-renewable energy is damaging to the environment and pollutes the atmosphere and water. This can make the issue of water scarcity even worse! |
| As we saw earlier, one common cause of water scarcity is dam construction. Because dam construction can result in one country essentially depriving another of water, it can result in tensions and/or conflict. So much so, that many people expect the next wars to be about water. | When people have to resort to treating water to meet demands, more money has to be spent on water management and water treatment facilities. The cost can create economic problems. | Water over-abstraction can cause the land to sink. We call this 'subsistence'. |
That table has a lot of information to take in! In Geography, it's really important to back up your points with case studies and real life examples. So, let's take a look at the part of the world which is the most 'water-scarce'.
The MENA (Middle East and Northern Africa) region is the most water-scarce place in the world. This is due to many of the reasons that we discussed, from dam construction to over-abstraction, pollution and the effects of climate change. Here are some facts and figures to show how significant the effects of this water scarcity can be:
- One of the reasons for the 1967 Six-Day War (between Syria and Israel) was tensions between the countries arising from the fact that they both share a water source (the River Jordan) and argued that the water wasn't being distributed fairly between the countries.
- Saudi Arabia has had to reduce its production of cereal by 12% per year to try and conserve water. This means that the money the country gets from exporting cereal will decrease considerably, which could impact their economy.
- 28% of species that are threatened by extinction in the MENA region are fish. Reasons for their vulnerability include physical water scarcity and the contamination of freshwater sources through oil spills and pesticides.
Solutions to water scarcity
This all sounds very concerning - right? Well, luckily for everybody there are ways that water scarcity can be managed. The main ways that this can be achieved are through increasing / conserving water supply and reducing the demand for water.
Some common examples of increasing water supply are creating dams (though we know this can be complicated), increasing water transfer schemes between places of water surplus and water deficit and building desalination plants so that seawater can be made safe for human consumption.
Fig. 4 - Water treatment (desalination) plant in Port Stanvac, Australia
Some examples of decreasing water demand are increasing the price of water and introducing incentives to encourage people to use less water in their day-to-day lives. Though this may negatively affect those who can't afford to pay for water.
You can read more about the potential solutions to water scarcity in our explanation on Water management.
Water Scarcity - Key takeaways
- Water scarcity occurs when there is not enough water to meet the needs of the population. Water scarcity can be physical (where there is just not enough water) or economic (where the water available isn't safe for use).
- Water scarcity can be caused by over-abstraction, pollution, dam construction and climate change.
- It has many social, economic and environmental impacts. Some of these include illness, disease, death, conflict, economic decline and biodiversity loss.
References
- Fig. 2: Grand Renaissance dam (https://commons.wikimedia.org/wiki/File:Grand-Ethiopian_dam.jpg) by शीतल सिन्हा (https://commons.wikimedia.org/w/index.php?title=User:%E0%A4%B6%E0%A5%80%E0%A4%A4%E0%A4%B2_%E0%A4%B8%E0%A4%BF%E0%A4%A8%E0%A5%8D%E0%A4%B9%E0%A4%BE&action=edit&redlink=1) licensed by CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/deed.en)
- Fig. 3: Unsafe water (https://commons.wikimedia.org/wiki/File:Hindastandaky_suw_%C3%BDetmez%C3%A7ilik_meselesi.jpg) by Orazgeldiyew (https://commons.wikimedia.org/wiki/Special:Contributions/Orazgeldiyew) licensed by CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/deed.en)
- Fig. 4: Water desalination plant (https://commons.wikimedia.org/wiki/File:Port_Stanvac_Desalination_Plant_P1000725.jpg) by User:Vmenkov (https://commons.wikimedia.org/wiki/User:Vmenkov) licensed by CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0/deed.en)
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