BEIJING - Glaciers in the Tianshan mountains of Xinjiang, near China's western border, are shrinking at "alarming speeds," the Xinhua news agency said on Thursday, citing a local scientist.

The No.1 glacier in the Tianshan mountains has lost 20 million cubic meters of ice in the past four decades, and split in half in 1993.

The eastern and western sections are receding by 3.5 meters and 5.9 meters every year, said Wang Feiteng, an assistant researcher with the Tianshan Mountain glacier monitoring station under the Chinese Academy of Sciences (CAS).

"Like the hard drive of a computer, glaciers record how the environment has changed. Warm weather has been the major cause of the glacier's retreat," Xinhua cited Wang as saying.

China has about 46,000 glaciers, totaling 60,000 square kilometers, primarily in Tibet and Xinjiang.

The total glacier area in Xinjiang, home to two-fifths of China's glaciers, has shrunk by 20 percent and snow lines have receded about 60 meters since 1964. CAS statistics show the internal temperature of the glaciers has risen by 10 percent in the last two decades, Xinhua said.

Beijing has become increasingly concerned about global warming, as studies show glaciers retreating on the Tibet-Qinghai plateau, where the country's largest rivers originate. Global warming could bring drought to China's arid regions and flooding to low-lying cities and arable land, scientists warn.

Summer flooding along the Huai River in central China has forced about half a million people to evacuate their homes in poor villages in Anhui, Henan and Jiangsu provinces.