A monitoring system has started to record environmental changes at the sources of China's three major rivers -- its two longest, the Yangtze and Yellow rivers, and the Lancang River.

The system will record and provide firsthand information on the growth of pasture, soil conditions, the area of desert and semi-desert land and rainfall, said an official with the local weather bureau.

The government expects the system to help form a complete picture of environmental changes in the sources of the three rivers, which is critical for both the climate and environment of China and the whole world, the official said.

With the application of satellite remote sensing and global positioning system, the local authorities bought 35 sets of advanced meteorological equipment from Finland.

The sources of the Yangtze, Yellow and Lancang rivers are all located in northwest China's Qinghai Province, covering an area of 318,000 square kms.

Due to long-term drought, over-farming and over-herding, the environment in this area has deteriorated in the past four decades.

The water flow in the upper reaches of the Yellow River has fallen by 9.8 cubic meters per second every decade.

Ten years ago there were 4,077 lakes in the Madoi County near the source of the Yellow River. According to last year's survey, 2,017 lakes disappeared and the rest are shrinking.

The Chinese government has set up a national nature reserve in the area, the largest of its kind.

(Xinhua News Agency October 6, 2002)