Mountains are seen in Chindu County, Yushu Tibetan Autonomous Prefecture, northwest China's Qinghai Province, Oct. 29, 2020. Sanjiangyuan region, or the sources of three rivers, namely the Yangtze River, Yellow River, and Lancang (Mekong) River, has seen its ecological environment improved a lot and wild animals increased obviously in recent years through the efforts of local government. (Xinhua/Zhang Long)

A Tibetan fox is seen in Chindu County, Yushu Tibetan Autonomous Prefecture, northwest China's Qinghai Province, Oct. 29, 2020. Sanjiangyuan region, or the sources of three rivers, namely the Yangtze River, Yellow River, and Lancang (Mekong) River, has seen its ecological environment improved a lot and wild animals increased obviously in recent years through the efforts of local government. (Xinhua/Zhang Long)

Aerial photo taken on Oct. 30, 2020 shows a wetland in Madoi County, Golog Tibetan Autonomous Prefecture, northwest China's Qinghai Province. Sanjiangyuan region, or the sources of three rivers, namely the Yangtze River, Yellow River, and Lancang (Mekong) River, has seen its ecological environment improved a lot and wild animals increased obviously in recent years through the efforts of local government. (Xinhua/Zhang Long)

Aerial photo taken on Oct. 30, 2020 shows a wetland in Madoi County, Golog Tibetan Autonomous Prefecture, northwest China's Qinghai Province. Sanjiangyuan region, or the sources of three rivers, namely the Yangtze River, Yellow River, and Lancang (Mekong) River, has seen its ecological environment improved a lot and wild animals increased obviously in recent years through the efforts of local government. (Xinhua/Zhang Long)

Aerial photo taken on Oct. 30, 2020 shows the Xingxinghai Lake in Madoi County, Golog Tibetan Autonomous Prefecture, northwest China's Qinghai Province. Sanjiangyuan region, or the sources of three rivers, namely the Yangtze River, Yellow River, and Lancang (Mekong) River, has seen its ecological environment improved a lot and wild animals increased obviously in recent years through the efforts of local government. (Xinhua/Zhang Long)

Tibetan donkeys forage in Madoi County, Golog Tibetan Autonomous Prefecture, northwest China's Qinghai Province, Oct. 30, 2020. Sanjiangyuan region, or the sources of three rivers, namely the Yangtze River, Yellow River, and Lancang (Mekong) River, has seen its ecological environment improved a lot and wild animals increased obviously in recent years through the efforts of local government. (Xinhua/Zhang Long)

Aerial photo taken on Oct. 30, 2020 shows a lake in Madoi County, Golog Tibetan Autonomous Prefecture, northwest China's Qinghai Province. Sanjiangyuan region, or the sources of three rivers, namely the Yangtze River, Yellow River, and Lancang (Mekong) River, has seen its ecological environment improved a lot and wild animals increased obviously in recent years through the efforts of local government. (Xinhua/Zhang Long)

Landforms of the Sanjiangyuan are seen in Madoi County, Golog Tibetan Autonomous Prefecture, northwest China's Qinghai Province, Oct. 30, 2020. Sanjiangyuan region, or the sources of three rivers, namely the Yangtze River, Yellow River, and Lancang (Mekong) River, has seen its ecological environment improved a lot and wild animals increased obviously in recent years through the efforts of local government. (Xinhua/Zhang Long)

A Tibetan antelope is seen on a grassland in Chindu County, Yushu Tibetan Autonomous Prefecture, northwest China's Qinghai Province, Oct. 29, 2020. Sanjiangyuan region, or the sources of three rivers, namely the Yangtze River, Yellow River, and Lancang (Mekong) River, has seen its ecological environment improved a lot and wild animals increased obviously in recent years through the efforts of local government. (Xinhua/Zhang Long)

Aerial photo taken on Oct. 30, 2020 shows Bayan Har Mountains covered with snow in Madoi County, Golog Tibetan Autonomous Prefecture, northwest China's Qinghai Province. Sanjiangyuan region, or the sources of three rivers, namely the Yangtze River, Yellow River, and Lancang (Mekong) River, has seen its ecological environment improved a lot and wild animals increased obviously in recent years through the efforts of local government. (Xinhua/Zhang Long)

An ecological protector picks up rubbish on a grassland in Chindu County, Yushu Tibetan Autonomous Prefecture, northwest China's Qinghai Province, Oct. 28, 2020. Sanjiangyuan region, or the sources of three rivers, namely the Yangtze River, Yellow River, and Lancang (Mekong) River, has seen its ecological environment improved a lot and wild animals increased obviously in recent years through the efforts of local government. (Xinhua/Zhang Long)