LANZHOU, March 22 -- Glaciers in the Qilian Mountains in northwest China's Gansu Province have shrunk by 36 square kilometers, an 4.2 percent retreat, during the past decade, the provincial meteorological station said Tuesday.

The area of snow cover on the mountains has also seen an average reduction of 290 square kilometers annually since 1997, it said.

The melting glaciers have caused inland rivers downstream in the provinces of Gansu and Qinghai to swell in the short term, but the water supply of these rivers is expected to decrease in the long term, said Zhang Qiang, deputy director of the station.

Glaciers on the mountains have reduced by 168 square kilometers since 1956, with lost glacial ice storage totaling 7 billion cubic meters.

Zhang attributed the shrinking glaciers to global warming. The average temperature of Gansu Province has climbed at a rate of 0.26 degrees Celsius per decade.