Experts believe the Yangtze River source is to have stable and sustained glacial alimentation as glaciers in the Geladandong region, source of the Yangtze River, haven?t reduced dramatically in the last 30 years, despite low water levels the river suffered this year.
The Yangtze River dropped to its lowest water level this year, and in the last 10 years, especially in the Three Gorges area where runoff has lowered by more than 3,000 cubic meters per second. However, related experts having carried out comprehensive research recently conclude that the water source of the Yangtze River will not dry up.
Glaciers in the Geladandong area, source of the Yangtze River on the Qinghai-Tibet Plateau, didn?t retreat to any large degree in the last 30 years as parts of them advance, Director of the Water Resources Department of China?s Ministry of Water Resources Wu Jisong explained, adding that glacial conditions there indicate the source of the Yangtze River has stable and sustaining glacial thawing alimentation.
Comparative analysis and comprehensive research on some 70 glaciers covering 899 square kilometers of the Geladandong region, conducted by related experts, show the glacial area in the region has not changed dramatically in general. In the 31-year period from 1969 to 2000, the glacial area has reduced by 1.7 percent, while 26 glaciers were in state of advancing.
Glacier shrinkage degree in this region is far less than that of the Tianshan Mountains, Qilian Mountains, Yellow River source and south and southeast parts of Qinghai-Tibet Plateau. The glacier area of Tianshan Mountains experienced a reduction of 13.8 percent from 1964 to 1993, Qilian Mountains a reduction of 10.3 percent from 1956 to 1990, while the glacier area in the Yellow River source district has reduced by 17 percent since 1969.
Glaciers in the Yangtze River source area belong to a class of extreme continental glaciers which feature extremely cold climates and comparatively rare precipitation, making for low ice temperatures and slow moving speeds of the glaciers. Glaciers of this class are less sensitive to climate change compared with other classes. As glaciers in Geladandong retreat to a minor extent, the Yangtze River source could get stable glacial alimentation thawing. Therefore, experts think the glaciers there play an important role in preserving benign development of the surrounding eco-environmental system.
(China.org.cn by Zhang Tingting, April 12, 2003)
