The half-frozen lake turns aquamarine blue in Sanjiangyuan National Park, Northwest China's Qinghai province, Nov 13, 2017.

China has invested some 17.6 billion yuan($2.8 billion) in improving the Sanjiangyuan area, the source of China's major rivers.

Sanjiangyuan in Northwest China's Qinghai province, literally means the "source of three rivers," is home to the headwaters of the Yangtze, Yellow, and Lancang (Mekong) rivers.

An ecological protection program began in the area in 2005 with 7.6 billion yuan invested during the first phase.

The second phase started at the beginning of 2014 and nearly 10 billion yuan has been spent since then.

During the past four years, the area has seen improving grassland and better water conservation due to a reduction of invasive animals and plants. Vegetation coverage of desertified land has grown from 33.4 percent to 39.4 percent and wetland coverage has grown by 4.7 percent.

Wildlife, such as snow leopard, jackal and Chinese grouse, is doing well.

Green animal husbandry, ecological tourism and the policy of eco-compensation have improved the lives of local people with per capita income up 35 percent from 2013.