Sanjiangyuan, a major natural reserve in northwestern China, saw rising vegetation coverage in 2019, according to the latest monitoring data.

Sanjiangyuan, meaning the "source of three rivers," is home to the headwaters of the Yangtze, Yellow and Lancang rivers.

The environmental quality remained stable in the area compared with the previous year, with grassland coverage reaching 77 percent, according to the report released by authorities of Qinghai Province.

The coverage of multiple types of forests, as well as the vegetation coverage and biomass in the wetlands, has also been on the rise, the report said.

Beginning in 2005, China launched the country's biggest ecological project to protect and restore the environment in Sanjiangyuan. In 2016, China started piloting the Sanjiangyuan National Park.