LHASA, March 28, 2016 (Xinhua) -- Photo taken on Aug. 19, 2013 shows the greenbelt at the river valley of Yarlung Zangbo River nearby the Lhasa Gonggar Airport, southwest China's Tibet Autonomous Region. (Xinhua/Chen Tianhu)

LHASA, March 28, 2016 (Xinhua) -- Photo taken on Sept. 10, 2012 shows the scenery of Yarlung Zangbo River in Xigaze, southwest China's Tibet Autonomous Region. (Xinhua/Chen Tianhu)

LHASA, March 28, 2016 (Xinhua) -- Photo taken on June 27, 2014 shows the wild yaks in northern part of southwest China's Tibet Autonomous Region. (Xinhua/Chen Tianhu)