Beijing: Glaciers in southwest China's Qinghai-Tibetan Plateau, a key source of major rivers in this country and those in the Indian subcontinent, are melting "faster than ever" under the influence of global warming, Chinese researchers have warned.

Experts have been conducting research on the waters, geology, glaciers and wetlands in the headwaters of Yangtze, Yellow and Lancang rivers in northwest China's Qinghai province since 2005.

There is no mention about the possible affects on Brahmaputra and Sutluj rivers which also emanate from Tibet.

Results from the study show that a large area of the glaciers has melted in the 2,400-square-kilometre region.

Glaciers are the largest source of fresh water on the planet. They are also a reliable indicator of climate change, and easy for scientists to observe.

An expert with Qinghai's Three-River Headwaters Office said the cluster of some 80 glaciers around the Aemye Ma-chhen Range, the source of the Yellow River headwaters, is shrinking especially fast.

"I can sometimes see the Ameye Ma-chhen Range on the plane. But I worry that we are not likely to see the glaciers there in ten years or more," the official Xinhua news agency quoted Li Xiaonan, deputy head of the office, as saying.

Cheng Haining, a senior engineer with the provincial surveying and mapping bureau, said about 5.3 percent, or 70 square kilometres, of the glaciers in Yangtze headwaters had melted away over the past three decades. Cheng said that "the melting of glaciers is closely connected with climate change."

He said the data collected by three meteorological stations over the past 50 years show a continued rise in the average temperature of the three-river headwaters area.

The winter of 2009, for example, was the warmest in 15 years, according to the provincial climate centre. Last year the average temperature there hit a five-decade record high.

Local residents in Yushu Tibet Autonomous Prefecture said Lancang River froze in November in the 1970s, but it did not freeze at all in 1999.

It is estimated that 70 percent of the glaciers in Lancang River headwaters have disappeared due to the warm weather, researchers said.

Besides climate change, experts said that human activities and excessive exploitation account for the melting of glaciers.

Xin Yuanhong, a senior engineer with the Qinghai Hydrography and Geology Study Centre, said the melting of the glaciers could lead to a water shortage and even a dry-up of rivers in the long run, and consequent ecological disasters like wetland retreat and desertification.

"The Qinghai-Tibetan Plateau is among the regions worst hit by global warming. Consequently, this will have a deleterious effect on the global climate as well as the livelihood of Asian people," Qin Dahe, a researcher with the Chinese Academy of Sciences, said.

Experts called for intensified efforts in conducting further studies on glaciers, and setting up a database to monitor glacier change in the three-river headwaters region.