The world's aquifers are drying up, threatening the drinking water supplies of millions and worsening drought and famine, according to a study released yesterday by the U.N. Environment Program prior to World Environment Day, whose theme this year is "Water -- 2 Billion People Are Dying For It!"

Intensive irrigation is largely to blame for groundwater levels that are dropping as much as 10 feet a year across Africa, Asia, Central and South America, according to Groundwater and Its Susceptibility to Degradation.  As the water tables drop, seawater seeps in at the coastline.

UNEP Executive Director Klaus Toepfer said that with as many as 2 billion people and as much as 40 percent of the world's agriculture reliant on groundwater stores -- which also feed springs and wetlands -- aquifers are a crucial part of the world's water supply.

Their demise is hidden, however, and therefore out of the public eye, he said.

"If a lake, reservoir or river becomes depleted or dries up, the event is highly visible," Toepfer said, "there is public outcry and often action taken.  I hope that this report will serve as a wake-up call concerning the human, social and economic consequences of squandering our vital underground water supplies" (Ed Johnson, Associated Press, June 4).

In parts of very dry and arid regions such as the Arabian Gulf, however, flooding is being caused by leaked desalinated water (UNEP release, June 5).  According to British hydrogeologist and study co-author John Chilton, groundwater is rising in Riyadh, Saudi Arabia.  He said water leaking from pipes and storage tanks has caused the water table to rise by as much as 16 inches a year and flooded basements (Johnson, AP).

In many places, however, aquifers are shrinking.  In Mexico the number of groundwater reservoirs considered overtaxed has quadrupled since 1975 to 130.  In Spain, more than half of the country's 100 aquifers are overexploited.  In the U.S. state of Arizona, groundwater is being pumped out twice as fast as nature is replenishing it.

On the eve of World Environment Day, Toepfer said, "We are here in Lebanon for World Environment Day, the first time the event has been held in the Arab world.  This report will have particular resonance in a region where it is estimated that in some areas over 90 percent of the population could be suffering water stress by 2032" (UNEP release).

A World Bank statement released for World Environment Day says climate change is exacerbating water scarcity and disproportionately affecting the poor, a situation that is likely to worsen in coming years.  The bank also says the number of people affected by water scarcity is expected to rise by 2025 to 5 billion.

"If the international community does not take decisive action to support developing countries in mitigating the potential impacts of climate change and implementing adaptive strategies, these dramatic projections may become a reality," said World Bank Director of Environment Kristalina Georgieva, adding, "At the national level, we must develop mechanisms capable of integrating climate change concerns into economic planning" (World Bank release, June 4).

Food and Agriculture Organization Director General Jacques Diouf urged world governments to "help safeguard the source of food security on our planet."

"I am convinced that if all countries concerned made better agricultural water management a political and financial priority, we would experience fewer disasters like the current food crisis in southern Africa and in the Horn of Africa," Diouf said.  The FAO estimates that in 30 years the world will require 60 percent more food (FAO release, June 5).