Aerial photo taken on April 16, 2019 shows the Yellow River passing through a canyon near Songba Village of Garang Township in Guide County, the Tibetan Autonomous Prefecture of Hainan, northwest China's Qinghai Province. Guide County, located in the upper stream of the Yellow River, is the transition zone between the Loess Plateau and the Qinghai-Tibet Plateau. (Xinhua/Zhang Hongxiang)