Members to maintain ecological security patrol to collect garbage in a village of Madoi County, Golog Tibetan Autonomous Prefecture, northwest China's Qinghai Province, Aug. 19, 2020. Sanjiangyuan, meaning the "source of three rivers," is home to the headwaters of the Yangtze, Yellow and Lancang rivers. To improve the local ecological environment, members to maintain ecological security of local monitoring stations play a key role in retrieving litters, protecting grasslands, monitoring animals and preventing poaching. (Xinhua/Zhang Long)

Members to maintain ecological security patrol to collect garbage at the Ngoring Lake, in northwest China's Qinghai Province, Dec. 2, 2018. Sanjiangyuan, meaning the "source of three rivers," is home to the headwaters of the Yangtze, Yellow and Lancang rivers. To improve the local ecological environment, members to maintain ecological security of local monitoring stations play a key role in retrieving litters, protecting grasslands, monitoring animals and preventing poaching. (Xinhua/Zhang Long)

A member to maintain ecological security patrols to check windbreak trees at Sengdo Township of Guinan County, northwest China's Qinghai Province, Sept. 10, 2013. Sanjiangyuan, meaning the "source of three rivers," is home to the headwaters of the Yangtze, Yellow and Lancang rivers. To improve the local ecological environment, members to maintain ecological security of local monitoring stations play a key role in retrieving litters, protecting grasslands, monitoring animals and preventing poaching. (Xinhua/Wu Gang)

A member to maintain ecological security patrols to collect garbage at a village of Madoi County, Golog Tibetan Autonomous Prefecture, northwest China's Qinghai Province, Aug. 19, 2020. Sanjiangyuan, meaning the "source of three rivers," is home to the headwaters of the Yangtze, Yellow and Lancang rivers. To improve the local ecological environment, members to maintain ecological security of local monitoring stations play a key role in retrieving litters, protecting grasslands, monitoring animals and preventing poaching. (Xinhua/Zhang Long)

A member to maintain ecological security patrols to check windbreak trees at Sengdo Township of Guinan County, northwest China's Qinghai Province, Sept. 10, 2013. Sanjiangyuan, meaning the "source of three rivers," is home to the headwaters of the Yangtze, Yellow and Lancang rivers. To improve the local ecological environment, members to maintain ecological security of local monitoring stations play a key role in retrieving litters, protecting grasslands, monitoring animals and preventing poaching. (Xinhua/Wu Gang)

Members to maintain ecological security patrol to collect garbage at the Ngoring Lake, in northwest China's Qinghai Province, Dec. 2, 2018 Sanjiangyuan, meaning the "source of three rivers," is home to the headwaters of the Yangtze, Yellow and Lancang rivers. To improve the local ecological environment, members to maintain ecological security of local monitoring stations play a key role in retrieving litters, protecting grasslands, monitoring animals and preventing poaching. (Xinhua/Zhang Long)