Aerial photo taken on Dec. 21, 2019 shows the view of Baidicheng in southwest China's Chongqing. In recent years, Chongqing has continuously built up important ecological barriers in the upper reaches of the Yangtze River by strengthening ecological restoration. The ecological environment in the Chongqing section of the Yangtze River has been continuously improved. (Xinhua/Wang Quanchao)
