Satellite data released by the University of California, Irvine, shows the world's water supply is disappearing fast because of agricultural demand, an expanding population, energy production and climate change, with the Middle East, Africa and Asia in particular facing crisis in the next few years.

Another study, this time from the Pacific Institute of Oakland, Calif., which monitors global water and security issues, reports a fourfold increase in violent confrontations over water in the last 10 years.

Together, these studies present an extremely bleak picture of how vast areas of the planet, from California to the Asian Steppe, are heading for severe, and probably deadly, water shortages.

"I think the risk of conflicts over water is growing -- not shrinking -- because of bad management and, ultimately, because of the impact of climate change," Pacific Institute director and co-founder Peter Gleick told the British newspaper the Guardian.

The data obtained by the University of California was downloaded Jan. 17 from two gravity-sensing Grace satellites, two craft lofted into space from Russia's Plesetsk Cosmodrome March 17, 2002, as part of the Gravity Recovery and Climate Experiment jointly run by the U.S. National Aeronautical and Space administration and the German Aerospace Center.

These satellites are considered cutting-edge tools in studying Earth's oceans, geology and climate and reputedly have produced maps 1,000 times more accurate than all previous maps.

James Famiglietti, a hydrologist at the University of California, notes that on the satellite images the biggest water losses appeared as red hotspots.

"Almost all of those correspond to major aquifers of the world," he said in the report. "What Grace shows us is that groundwater depletion is happening at a very rapid rate in almost all of the major aquifers in the arid and semi-arid parts of the world."

The water losses are immense. According to Grace mission data, published by the Guardian, in seven years starting in 2003, parts of Syria, Turkey, Iraq and Iran along the Euphrates and Tigris Rivers lost 144 cubic kilometers (34.5 cubic miles) of fresh water.

Iran is facing a shortage so severe, the government is making contingency plans for rationing in the greater Tehran area, which has a population of about 22 million.

Experts blame climate change, wasteful irrigation practices and a depletion of groundwater as the key factors behind the worsening shortages.

An Iranian dam construction program is seen as one major cause, a recurring element in the growing water shortage across the region.

Egypt's currently is at odds with Ethiopia over its construction of a $4.2 billion, 6,000-megawatt hydroelectric dam on the Blue Nile, a major tributary of the Nile, that Cairo claims will reduce the water flow that is Egypt's lifeline by 20 percent.

Addis Ababa refuses to abandon the Grand Renaissance Dam, which it views as vital to Ethiopia's national security.

Cairo has vowed to protect its "historical rights" to the lion's share of the Nile water, enshrined in British colonial-era agreements, "at any cost."

Water shortages in the United Arab Emirates are so severe the Persian Gulf federation is reported using non-conventional resources, such as desalination, treated wastewater and even cloud-seeding, to help it through the unfolding crisis.

"For us, water is now more important than oil," Gen. Sheik Mohammed bin Zayed al-Nahyan, the Emirati crown prince, told a recent international water conference in Abu Dhabi.

Jordan, which has the region's third lowest water reserves, reported last week its already limited water resources are being strained to the limit by the influx of 600,000 refugees from the Syrian civil war.

As the resource-poor Hashemite kingdom, which in the past has clashed with Israel over water, undergoes power cuts because of water shortages, Prince Hassan, uncle of King Abdullah II, warned a war over water and energy could be bloodier than the political upheavals sweeping the Arab world.

The University of California's Famiglietti warned time is running out for concerted action to head off the crisis.

"We're standing on a cliff looking over the edge and we have to decide what to do," he observed.

"Are we just going to plunge into this next epic drought and tremendous, never-before-seen rates of groundwater depletion, or are we going to buckle down and start thinking of managing critical reserve for the long term? We're standing on a precipice here."