BEIJING - China has invested 6.51 billion yuan ($1.1 billion) to protect Sanjiangyuan, the cradle of the Yangtze, Yellow and Lancang rivers in Northwest China's Qinghai province, according to the Ministry of Finance.

The money was used during a nine-year project, which ended at the end of 2013, intended to improve the Sanjiangyuan environment. Money was spent on wetlands protection, grazeland-to-grassland restoration, forest reservation and water and soil conservation.

The forest coverage rate in Sanjiangyuan increased from 3.2 percent in 2004 to 4.8 percent in 2012, and the wetlands restoration area has reached 1,067 square kilometers, the ministry said.

The Sanjiangyuan region has also seen its lakes swell. The surface area of lakes has increased by 2.84 billion cubic meters from 2004 to 2012.

Investment has helped solve water-drinking problems of 131,600 people and 360,000 livestock in the region, according to the ministry.

With an average altitude of 4,000 meters, the region is important for herders and rare wild animals such as the Tibetan antelope. It is also a place where medicinal herbs grow like the Tibetan snow lotus.

However, global warming and human activity since the end of last century have led to a deteriorating natural environment, shrinking wetlands, decreasing water levels in lakes and water flow in the headwaters, and increasing desertification.