Some 2.6 million hectares of grasslands have been restored in the Three-River Headwaters on the Qinghai-Tibet Plateau in the past four years for ecological protection, local authorities said Sunday.

The Three-River Headwaters, known as Sanjiangyuan in Chinese, is the source of China's three major waterways: the Yangtze, Yellow and Lancang rivers.

"We have spent more than 950 million yuan (139 million U.S. dollars) fencing pastures and subsidizing the herdsmen and restored 2.6 million hectares of grasslands from grazing," said Li Xiaonan, deputy director of the Sanjiangyuan ecological preservation and construction office of Qinghai Province.

"The total investment will reach 3.1 billion yuan to restore more than 6.4 million hectares," he said.

Sohe, deputy head of Chengduo County, Yushu Tibetan Autonomous Prefecture, said the number of livestock in the county has reduced by one third from the previous 800,000, which allowed the grasslands to recover.

The vegetation coverage rate within the fence has reached 90 percent, Li said.

The grasslands of the Three-River Headwaters have sharply deteriorated due to global warming and frequent human activities. Degraded grasslands can speed up soil erosion and desertification.

In 2005, the central government initiated a 7.5-billion-yuan ecologic reconstruction program in Sanjiangyuan area, with grasslands recovery as one of the 22 sub-projects.