Photo taken on Nov. 6, 2019 shows Shudu lake at Pudacuo National Park in Tibetan Autonomous Prefecture of Deqen in southwest China's Yunnan Province. (Xinhua/Hu Chao)

Aerial photo taken on Nov. 11, 2019 shows the scenery of Baishuitai scenic spot in Tibetan Autonomous Prefecture of Deqen in southwest China's Yunnan Province. (Xinhua/Hu Chao)

Blacknecked cranes rest at the Napahai Nature Reserve in Tibetan Autonomous Prefecture of Deqen in southwest China's Yunnan Province, Nov. 10, 2019. (Xinhua/Hu Chao)

Photomontage taken on Nov. 7, 2019 shows star trails above Meili Snow Mountains in Tibetan Autonomous Prefecture of Deqen in southwest China's Yunnan Province. (Xinhua/Hu Chao)