Scarcity of water in Asia could become a thorny issue for the region and trigger major conflicts, an expert says.

A rise in population, increased water use and the expectation that Asia will be most affected by global warming will affect the availability of water for the world's most populous continent.

Of even greater concern, warns Brahma Chellaney, author of "Water: Asia's New Battleground," are disputes and competition over bodies of water that cross boundaries of Asian countries, posing a threat to peace and stability.

"National reliance on oil can be reduced through other sources of energy," says Chellaney, professor of strategic studies at New Delhi's Center for Policy Research. "There is no such hope with water. Water has no substitute."

To avert a water war, Chellaney says, a cooperative Asian framework among river basin states is needed, with the aim of working toward a common ownership of shared resources.

But China seems to have an aversion to such a multilateral approach to water.

In an editorial published recently in The Japan Times, Chellaney pointed to "China's rise as a hydro-hegemon."

While China is the source of cross-border water flows to the largest number of countries in the world, Beijing "rejects the very notion of water sharing or institutionalized cooperation with down-river countries," Chellaney says.

On a global level, Chinese companies and Chinese banks are the biggest builders and financiers of dam building, involved in constructing some 251dams in 68 countries, especially in Southeast Asia and Africa, says environmental group International Rivers.

More locally, China is rapidly "accumulating leverage against its neighbors" through its massive hydro-engineering projects on transnational rivers, Chellaney wrote.

India, for example, is concerned about China's plans for a 38,000-megawat dam on the Brahmaputra River at Metog, near the disputed border between the countries.

The proposed Metog dam will be twice as large as China's 18,300-megawatt Three Gorges, now the world's largest dam, the construction of which uprooted some 1.7 million people in China.

China has also identified another spot on the Brahmaputra for a mega-dam at Daduqia.

Although China is building a series dams on Southeast Asia's Mekong River, it refuses to become a member of the Mekong River Commission, an inter-governmental agency whose members include Cambodia, Laos, Thailand and Vietnam.

But at a meeting in Cambodia last week focusing on Mekong River development and China's dam-building ambitions, a Chinese government official maintained that Beijing was "eager to participate" in regional cooperation mechanisms for water resources, The Phnom Penh Post reported.