Efforts taken to restore ecological environment in upper reaches of Yangtze River in Yunnan

File photo taken on Dec. 9, 2015 shows tourists visiting the Erhai Lake in Dali Bai Autonomous Prefecture, southwest China's Yunnan Province. To keep Yangtze River clean and beautiful, efforts to restore ecological environment have been taken in the upper reaches of Yangtze River in Yunnan Province in recent years. (Xinhua/Lin Yiguang)