** This factbox is part of AlertNet's special multimedia report on water. Visit "The Battle for Water" for more**
LONDON (AlertNet) - Water scarcity is both a natural and a human-made problem.
Population growth, rapid urbanisation, industrial development, rising agricultural needs and overuse of lakes, waterways and aquifers - all put pressure on water supplies.
Additional drivers of water scarcity include drought, desertification, rising sea levels and accelerated melting of glaciers, which scientists say are being exacerbated by climate change.
The technical definition of water scarcity is a complex equation based on demand for and use of water, and its supply. It is typically measured in terms of how much water is available to a person living in a particular place in a given year.
An area is said to experience water stress when annual water supplies drop below 1,700 cubic metres per person. If they are less than 1,000 cubic metres per person per year, the population is said to face water scarcity, and below 500 cubic metres,absolute scarcity.
These definitions are commonly used by the United Nations and water experts worldwide.
Water scarcity is a growing problem. By 2025, 1.8 billion people will be living in countries or regions with absolute water scarcity, while two-thirds of the world's population could be living under water-stressed conditions, according to the United Nations.
Here is information on some of the world's main hotspots for water scarcity, in no particular order, based on U.N. estimates and the views of water experts interviewed by AlertNet.
* Years of conflict and the absence of a functioning government since 1991 have left Somalia’s water infrastructure in tatters.
* Frequent droughts have been compounded by close to zero investment in water infrastructure, reservoirs and irrigation projects.
* Somalia lies in a region of extreme water scarcity with little rainfall. Most of its water comes from rivers shared with neighbouring countries.
* Demand for water in Somalia is increasing due to population and urban growth.
* Agriculture accounts for more than 90 percent of all water use in Somalia.
Sources: 4th U.N. World Water Development Report, 2012; U.N. Food and Agriculture Organisation (FAO)
* Rising sea levels threaten to inundate Egypt’s low-lying arable lands with seawater, making them too salty for some crops to grow and diminishing crop yields.
* The main challenge to the sustainability of Egypt’s water resources is water pollution.
* Population growth and sprawling urbanisation are putting additional pressure on Egypt’s scarce water resources.
* Pakistan is an arid, water-stressed country that will likely face outright water scarcity in the future.
* Glaciers act like water banks, storing fresh water and releasing it when they melt. Pakistan relies on water from Himalayan glaciers that release about 180 billion cubic metres of water each year into the Indus River and its tributaries.
* The shrinkage of ice caps and glaciers, due to rising temperatures linked to climate change, means glaciers have less water to release, affecting Pakistan’s water supplies.
* Water tables around Pakistan’s major cities are falling at accelerating rates.
Sources: World Bank; U.N. Human Development Report, 2006
PARTS OF INDIA
* Unless India changes the way it uses and manages water, it will face a severe water crisis within the next two decades, says the World Bank.
* By 2020, it is estimated that India’s demand for water will exceed all sources of supply.
* Rapid population growth and urbanisation are putting ever more pressure on water supplies as more people consume more water.
* In some parts of India, groundwater supplies are being depleted faster than they are being recharged.
* All of India’s 14 major river systems are badly polluted by raw sewage and industrial waste.
* Rapid melting of glaciers, especially in the western Himalayas, means farmers are finding it harder to access enough water.
* Water tables are falling in most states in India, and thousands of irrigation wells are going dry each year.
* Fast-dwindling underground water supplies in some farming communities in the western state of Gujarat have left agriculture dependent on rain, and drinking water has to be trucked in.
* Conflict over water use in Gujarat and Rajasthan has lead to repeated bouts of violence.
Sources: World Bank; FAO; U.N. Human Development Report, 2006; Earth Policy Institute
PARTS OF CHINA
* Demand for water is rising in China due to an expanding population, rapid economic growth, urbanisation and increased water use for agriculture, along with inefficient and outdated irrigation systems.
* Groundwater resources and rivers in some parts of China are being over-exploited, leading to water shortages and declining grain production.
* Industrial and agricultural waste has made some of China’s rivers too polluted to use for drinking water and agriculture. More than 80 percent of the Hai and Huai river basins are highly polluted.
* China’s water shortages are largely concentrated in the country’s dry north, which has only a fifth of the country’s water. Wheat harvests there are falling.
* China’s arid western region is likely to experience a decline in the volume of water flowing from glaciers, as they melt at an accelerating rate, affecting 300 million farmers.
Sources: FAO; U.N. Human Development Report, 2006
* Agriculture accounts for 90 percent of all water use in Yemen – one of the highest rates in the world.
* Nature cannot recharge groundwater fast enough to keep pace with growing demand for water from Yemen’s population of 23 million, which is expected to double by 2025.
* Yemen has one of the world’s fastest-growing populations and some of its fastest-falling water tables.
* Availability of fresh water in Yemen is among the lowest in the world.
* In the southern city of Taiz, tensions over water use and groundwater exploitation have led to violent confrontations.
* Farmers have protested about the transfer of water from agricultural use to fast-growing cities, such as Taiz and the capital Sanaa. (United Nations Human Development Report, 2006)
Sources: 4th U.N. World Water Development Report, 2012; U.N. Human Development Report, 2006; Earth Policy Institute
* Palestinians face one of the highest levels of water scarcity in the world, partly due to unequal sharing of water from aquifers in the occupied West Bank.
* Many Palestinians living in the West Bank rely on water bought from the Israeli national water company, Mekorot.
* In the West Bank, Israeli settlers consume an average of 620 cubic metres per person every year, and Palestinians less than 100 cubic metres.
Sources: U.N. Human Development Report 2006; World Bank report, 2009
* Saudi Arabia is oil-rich but water-poor.
* Due to severe water shortages, Saudi Arabia and other Gulf states have turned to desalination – treating salt water so it can be used for drinking and other purposes. But the process is expensive, energy-intensive and damages marine life.
* Saudi Arabia is the largest producer of desalinated water from the sea.
* Three-quarters of Saudi Arabia’s fresh water comes from non-renewable groundwater, which is being depleted fast.
* From 1980 to 2006, a boom in desert agriculture tripled the volume of water used for irrigation in Saudi Arabia.
Sources: Arab Water Council; U.N. Environment Programme; FAO
* Bahrain is one of the world’s most water-scarce countries, due to an increasing population, high consumption of water per person, low rainfall and shrinking groundwater resources. (FAO)
* Bahrain gets 75 percent of its water from outside its borders.
* The quantity and quality of Bahrain’s groundwater reserves are being depleted due to overuse, excessive pumping and seawater intrusion.
Sources: FAO; U.N. Human Development Report, 2006
* Jordan has one of the world’s lowest levels of water availability per person per year. (World Health Organisation
* A growing population and rising demand for water for agriculture and industrial growth are putting pressure on diminishing water supplies.
* Most of Jordan’s water resources are shared with other countries.
* About two-thirds of Jordan's water supplies go to agriculture, even though agriculture is responsible for less than 4 percent of gross domestic product.
Sources: World Health Organisation; Arab Water Council, Jordan country report 2011; FAO; U.N. Environment Programme