Photo 1：People take cable cars over Dianchi Lake in Kunming, southwest China's Yunnan Province, Nov. 14, 2017. The water quality of Dianchi Lake has been improved a lot after years of water ecosystem restoration and wastewater management. (Xinhua/Lin Yiguang)

Photo 2：Photos taken on Nov. 14, 2017 show the scenery of wetland by the Dianchi Lake in Kunming, southwest China's Yunnan Province. The water quality of Dianchi Lake has been improved a lot after years of water ecosystem restoration and wastewater management. (Xinhua/Lin Yiguang)

Photo 3：Workers collect waste from a river that flows into Dianchi Lake in Kunming, southwest China's Yunnan Province, Sept. 12, 2017. The water quality of Dianchi Lake has been improved a lot after years of water ecosystem restoration and wastewater management. (Xinhua/Lin Yiguang)