Over the past 2 centuries, the World’s population has grown at a very rapid exponential rate. It has grown by over 5 billion people since 1900 and all of these people have demands on the World’s fresh water. Most of this growth has been in LICs and NICs. According to the UN, people need at least 20 litres of clean water per day for their basic needs. However, the UN also state that over 1.7 billion people are currently living in river basins where water use exceeds supply and that 2.4 billion people lack access to basic sanitation services, such as toilets. This has had a big impact on the domestic water uses, but also increased demand on the use of water for both food production (agriculture) and industry. This can be seen on the graph, which shows total water withdrawals increasing with global population. The rate of population growth is slowing down however.
There is also a pattern between the level of development of a place and how much water is consumed. Many countries are developing at a rapid rate across the world and this increases water consumption through;
1. Rising Living Standards – people in countries that have become richer have more money to spend on items that consume water such as dishwashers, washing machines, flushing toilets and showers. People also tend to eat more meat as living standards increase, which also needs more water in its production.
2. Industrial growth – this consumes water in many ways, so as countries develop their manufacturing industries consume more water.
3. Farming – this has changed with increasing economic development. Modern commercial agriculture uses huge amounts of water in irrigation systems. On the graph above you can see that this is the biggest user of water.
4. Virtual water – This is the water that moves around the world because it is embedded in farm products and manufactured goods. It refers to the hidden flow of water if food or other commodities are traded from one place to another. For instance, it takes 1,340 cubic meters of water to produce one metric tonne of wheat.
There are huge inequalities in water use between countries. Generally, the greater the wealth and standard of living in a country the higher the per person consumption of water. It is interesting to see on the graph above that the middle-income countries or NICs have similar water consumption rates to those HICs.
What is water used for – agriculture, industry and domestic uses
Freshwater is used for a huge range of purposes including;
1. Farming or agricultural uses – the water is needed for watering (irrigating) crops, and drinking water for animals. Irrigation varies from automatic sprinklers, which use huge amounts of water, to simpler gravity fed models from local rivers and lakes.
2. Industrial use – water is used to make things such as food products, in processing and in cooling.
3. Energy uses – water is essential for producing HEP (Hydro Electric Power) and for steam needed to drive turbines in fossil fuel powered and nuclear powered power stations (like Ikata nuclear power plant opposite). It is also used to provide cooling in thermal power stations.
Ikata Nuclear Power Plant, Japan By ja:User:Newsliner - Own work, CC BY-SA 2.5,
4. Domestic uses, including drinking, cooking and washing also consume water
5. Leisure uses – these include watering parks and golf courses, filling swimming pools and for things like water skiing.
These uses vary from place to place depending upon the level of development of the place. The USA has a much greater withdrawal for its agriculture and industrial uses than the Republic of the Congo.
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