Aerial photo taken on May 25, 2021 shows a view of Ngoring Lake in the Sanjiangyuan National Park in Golog Tibetan Autonomous Prefecture of northwest China's Qinghai Province. Sanjiangyuan, meaning the "source of three rivers," is home to the headwaters of the Yangtze, Yellow and Lancang rivers. The ecological system has been steadily improving in recent years in the Sanjiangyuan National Park, making it a habitat of an increasing number of wild animals. [Photo by Li Zhanyi/Xinhua]

A Tibetan donkey is seen at the source of the Yellow River section of the Sanjiangyuan National Park in Golog Tibetan Autonomous Prefecture of northwest China's Qinghai Province, May 25, 2021. Sanjiangyuan, meaning the "source of three rivers," is home to the headwaters of the Yangtze, Yellow and Lancang rivers. The ecological system has been steadily improving in recent years in the Sanjiangyuan National Park, making it a habitat of an increasing number of wild animals. [Photo by Zhang Long/Xinhua]

Aerial photo taken on May 25, 2021 shows a view of Ngoring Lake in the Sanjiangyuan National Park in Golog Tibetan Autonomous Prefecture of northwest China's Qinghai Province. Sanjiangyuan, meaning the "source of three rivers," is home to the headwaters of the Yangtze, Yellow and Lancang rivers. The ecological system has been steadily improving in recent years in the Sanjiangyuan National Park, making it a habitat of an increasing number of wild animals. [Photo by Li Zhanyi/Xinhua]

A Tibetan antelope is seen at the source of the Yellow River section of the Sanjiangyuan National Park in Golog Tibetan Autonomous Prefecture of northwest China's Qinghai Province, May 25, 2021. Sanjiangyuan, meaning the "source of three rivers," is home to the headwaters of the Yangtze, Yellow and Lancang rivers. The ecological system has been steadily improving in recent years in the Sanjiangyuan National Park, making it a habitat of an increasing number of wild animals. [Photo by Zhang Long/Xinhua]

A Tibetan fox is seen at the source of the Yellow River section of the Sanjiangyuan National Park in Golog Tibetan Autonomous Prefecture of northwest China's Qinghai Province, May 25, 2021. Sanjiangyuan, meaning the "source of three rivers," is home to the headwaters of the Yangtze, Yellow and Lancang rivers. The ecological system has been steadily improving in recent years in the Sanjiangyuan National Park, making it a habitat of an increasing number of wild animals. [Photo by Zhang Long/Xinhua]

An eagle is seen at the source of the Yellow River section of the Sanjiangyuan National Park in Golog Tibetan Autonomous Prefecture of northwest China's Qinghai Province, May 25, 2021. Sanjiangyuan, meaning the "source of three rivers," is home to the headwaters of the Yangtze, Yellow and Lancang rivers. The ecological system has been steadily improving in recent years in the Sanjiangyuan National Park, making it a habitat of an increasing number of wild animals. [Photo by Zhang Long/Xinhua]

A herd of Tibetan donkeys are seen at the source of the Yellow River section of the Sanjiangyuan National Park in Golog Tibetan Autonomous Prefecture of northwest China's Qinghai Province, May 25, 2021. Sanjiangyuan, meaning the "source of three rivers," is home to the headwaters of the Yangtze, Yellow and Lancang rivers. The ecological system has been steadily improving in recent years in the Sanjiangyuan National Park, making it a habitat of an increasing number of wild animals. [Photo by Zhang Long/Xinhua]

Two Tibetan donkeys are seen at the source of the Yellow River section of the Sanjiangyuan National Park in Golog Tibetan Autonomous Prefecture of northwest China's Qinghai Province, May 25, 2021. Sanjiangyuan, meaning the "source of three rivers," is home to the headwaters of the Yangtze, Yellow and Lancang rivers. The ecological system has been steadily improving in recent years in the Sanjiangyuan National Park, making it a habitat of an increasing number of wild animals. [Photo by Zhang Long/Xinhua]

A Tibetan donkey is seen at the source of the Yellow River section of the Sanjiangyuan National Park in Golog Tibetan Autonomous Prefecture of northwest China's Qinghai Province, May 25, 2021. Sanjiangyuan, meaning the "source of three rivers," is home to the headwaters of the Yangtze, Yellow and Lancang rivers. The ecological system has been steadily improving in recent years in the Sanjiangyuan National Park, making it a habitat of an increasing number of wild animals. [Photo by Zhang Long/Xinhua]

Aerial photo taken on May 25, 2021 shows a view of Ngoring Lake in the Sanjiangyuan National Park in Golog Tibetan Autonomous Prefecture of northwest China's Qinghai Province. Sanjiangyuan, meaning the "source of three rivers," is home to the headwaters of the Yangtze, Yellow and Lancang rivers. The ecological system has been steadily improving in recent years in the Sanjiangyuan National Park, making it a habitat of an increasing number of wild animals. [Photo by Li Zhanyi/Xinhua]