Chinanews, Beijing, December 18 – According to a research by Qin Dahe, one of the most famous glaciologists in China, the total areaof glaciers in China has dropped by 7.4% in the past five years due to the effect of global warming. Qin calls for immediate investigation on the changes of the total volume of the glaciers.The researchers have surveyed about 20,000 sq km of glaciers without debris covers, most of which are shrinking. The glaciers in the Ili River Basin, the Junggar Basin, the upper stream of the Yarlung Zangbo River have already become 18% smaller.Glaciers serve as the most important water source to most population in western China and several major inland rivers. The average volume of glacier water in China is nearly the same as the annual flow of the Yellow River. Statistics show that there were 46,000-odd glaciers in China, with a total volume of 5,590 cubic km.