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Facts and figures about
For a quick overview, click on the "Water from the clouds" and "Transboundary water" infographics below.
Go to the Visualizations and infographics page for more visual presentations.
Precipitation and renewable freshwater resources
Only 2.5 percent of the water stored on earth is freshwater, the rest being oceans and other saline water.
Globally, the annual precipitation on land is about 814 mm or almost 110 000 km3, of which 56 percent is evapotranspired by forests and other natural landscapes and 5 percent by rainfed agriculture. The remaining 39 percent (or 42 920 km3) are the worldwide theoretically available annual renewable freshwater (surface water and groundwater) resources for human uses and the environment, which in 2014 is equal to about 5 800 m3 per person per year or 16 000 litres per person per day. While this seems to be enormous, unfortunately freshwater is very unevenly distributed geographically and a large part of it is not easily accessible.
Large differences in precipitation exist between continents, regions, countries and within countries:
Renewable freshwater resources
- The American continent is the most humid continent with a precipitation of 1 104 mm/year. However, this is because of the Latin America and Caribbean region which is the most humid region with more than 1 600 mm/year on average against only 637 mm/year for the Northern America region.
- The European continent receives less precipitation than the African continent, 545 mm/year against 677 mm/year. This is mainly due to the large arid areas of the Russian Federation. Precipitation in the Northern Africa region is 96 mm/year. The Western and Central Europe and Sub-Saharan Africa regions receive more or less the same amount of precipitation, around 800 mm/year. However climate is moderate in Europe, while hot temperatures in large regions of Africa can result in considerable losses of water through extremely high evaporation.
- The Asian continent is the most diversified continent: the Southern and Eastern Asia region is with 1 139 mm/year humid, while the Middle East region is amongst the driest regions in the world with the Arabian Peninsula sub-region receiving just 85 mm/year.
- Egypt is with only 51 mm/year the country with the lowest precipitation worldwide, followed by Libya with 56 mm/year and Saudi Arabia with 59 mm/year. However, thanks to the Nile river bringing a large amount of freshwater into Egypt each year, the renewable freshwater resources per person—1 900 litres per day in 2013—are much higher than in Libya—300 litres per day—and Saudi Arabia—230 litres per day, which both don’t benefit from external rivers.
- Countries with the highest precipitation are usually islands, such as Sao Tome and Principe in Africa with 3 200 mm/year, Papua New Guinea in Asia with 3 142 mm/year or the Solomon Islands in Oceania with 3 028 mm/year. Costa Rica in the Central America region is, with 2 926 mm/year, the continental country receiving the highest precipitation.
- For most parts of India the rainfall occurs under the influence of the southwest monsoon between June and September, accounting for 70-95 percent of the annual rainfall. However, in the southern coastal areas near the east coast much of the rainfall is influenced by the northeast monsoon during October and November. And while the average annual rainfall over the country is 1 170 mm, it varies from 150 mm in the northwest desert of Rajasthan to more than 10 000 mm on the Khasi hills in the northeast.
Depending on diet and lifestyle, about 2 000 to 5 000 litres of water is said to be used to produce a person’s daily food and meet the daily drinking water and sanitation requirements, so theoretically there is more than enough water available worldwide, even if taking into consideration the water needed to produce clothes and other consumable and non-consumable goods. However, as mentioned, freshwater is very unevenly distributed and a large part of it is not easily accessible.
While all continents have sufficient water resources to cover the daily requirements in 2013, large differences exist between continents, regions, countries and within countries:
- The American continent is the wettest continent with 46 percent of the world annual renewable freshwater resources for 30 percent of the global land area. The renewable freshwater resources per person are 55 500 litres per day.
- The South America region contains 29 percent of the world annual renewable freshwater resources for 13 percent of the global land area and is the region with the largest volume of freshwater resources per person: 86 600 litres per day.
- Oceania is the driest continent with only 2 percent of the world annual renewable freshwater resources for 6 percent of the global land area. It is, however, the continent where the renewable freshwater per person is the largest—81 000 litres per day—due to a low population density. But there are large regional and within country differences. Looking at for example Australia, unfortunately the population is concentrated in areas where water is already scarce.
- Asia is the continent with the lowest volume of renewable freshwater resources per person: 7 550 litres per day. China has 5 500 litres per person per day, but there are very large differences between the dry north and the humid south. India has only 4 200 litres per person per day, but also here with large differences between the dry northwest and the wetter east.
- In the Northern Africa and the Arabian Peninsula regions renewable freshwater resources are only 750 and 230 litres per person per day respectively.
- Iceland is the country with the largest volume of renewable freshwater resources per person: 1.4 million litres per day. Kuwait has the smallest volume per person: 16 litres per day.
- As an example: Just for domestic purposes, in rich countries water withdrawal can go up to 800 litres per person per day, against only 10 litres per person per day in very poor countries.
In addition to spatial differences, there are the temporal differences. In India, most of the renewable water resources are generated during the three month monsoon period during which 70-95 percent of the annual precipitation occurs.
Almost two-thirds of all countries of the world have rivers flowing into their territories from upstream countries.
There are 276 transboundary river basins worldwide that cover about half of the earth’s surface and account for about 60 percent of the global freshwater flows.
Seven countries share the Amazon river basin in Southern America region; eight countries share the Mekong river basin in the Southern and Eastern Asia region; eleven countries share the Nile river basin in Africa; nineteen countries share the Danube river basin in Europe, the Danube being the river crossing most countries.
About two billion people worldwide, or almost one third of the world population, depend on groundwater, which includes about 300 transboundary aquifer systems.
Canada and the Russian Federation have the largest dam capacities, over 800 km3 each. However, when scaled to country population, Suriname with over 42 500 m3/person largely exceeds Canada’s and Russian’s capacity, which is 25 000 m3/person and 5 700 m3/person respectively.
44 countries are landlocked worldwide, depriving them from the potentially important sources of desalinated water in the future.
About half of the world’s desalinated water is produced in the seven countries of the Arabian Peninsula. About 10 percent of the total is produced in the United States of America.
[Date of preparation: December 2014]
For a map, go to:
For regional-level data, go to:
For country-level data, go to:
1 km3 = 1 000 000 000 m3 = 400 000 Olympic-sized swimming pools (50x25x2m)
1 m3 = 1 000 litres = 35.3 cubic feet = 264.17 US gallons