Working staff pick rubbish and debris in Dianchi Lake in Kunming, capital of Southwest China’s Yunnan province, June 4, 2015. The water quality in the Dianchi Lake has been improved as wetlands and ecological forests were constructed along the lake. [Photo/Xinhua]

Working staff pick rubbish and debris in Dianchi Lake in Kunming, capital of Southwest China’s Yunnan province, June 4, 2015. The water quality in the Dianchi Lake has been improved as wetlands and ecological forests were constructed along the lake.[Photo/Xinhua]

Working staff pick rubbish and debris in Dianchi Lake in Kunming, capital of Southwest China’s Yunnan province, May 27, 2015. The water quality in the Dianchi Lake has been improved as wetlands and ecological forests were constructed along the lake.[Photo/Xinhua]