Population explosion, climate changes and rising demand amidst economic development are putting increasing pressures on the already tight water supply.

Surging production of ethanol and other biofuels as alternative energies also add new strains to the water shortage.

The World Water Forum which opened Tuesday in Istanbul has again drawn the world's attention to the problem threatening the very survival of mankind.

The latest UNESCO report on water resources predicts tight water supplies for nearly half of the world's population by 2030, and tens or even hundreds of millions of people would be forced to abandon their homes.

Usable fresh water on the earth is extremely limited, and many countries are faced with a water deficit. Competition for this valuable resource has mounted to conflicts in some regions. Water is one of the sources of bitterness between Arabs and Israelis in the Mideast and it has soured relations among many African nations.

More and more people around the world are becoming aware of the problem and its possible consequences. How to save and more effectively use water has dominated the agenda of governments around the world.

"With increasing shortages, good governance is more than ever essential for water management," Koichiro Matsuura, UNESCO director-general, said on the first day of the global water forum.

An effective management mechanism is vital for the realization of the economic use of water. There will be ways to address the problem as long as the world's nations show political will, analysts say.

The World Bank has come up with a concept as "tradable water rights" to replace traditional water allocation system. It advocates privatized water resources, which will be traded as commodities.

According to the concept, water is allowed to be sold within a country or exported at prices acceptable for both sellers and buyers.

Expanded investment is also needed to improve infrastructure to stop waste as it has been reported that even well-run water utilities in rich countries suffer leakages of between 10 and 30 percent.

Aid should also be encouraged to boost decent water supplies for poor nations, where scarce access to clean water has given rise to epidemics like diarrhea, which kills thousands of African children every day.

Matsuura has urged leaders who will gather for the group of eight richest nations in Italy in July to pledge more investment to help prevent a "major water crisis."

(Xinhua News Agency March 17, 2009)