Photo taken on June 21, 2018 shows the Xi'an Expo Park located within the Chanba Ecological District in Xi'an, northwest China's Shaanxi Province. Comprehensive progress has been made since the report delivered at the 18th National Congress of the Communist Party of China (CPC) in 2012 included ecological development as a major task in the country's overall plan and proposed building a "beautiful China" as a grand goal. (Xinhua/Shao Rui)

Aerial photo taken on June 23, 2018 shows wetland of the Yellow River Delta national natural reserve in Dongying, east China's Shandong Province. The Yellow River, the second longest river in China, originates on the Qinghai-Tibet Plateau and empties into the Bohai Sea from Dongying City. The city has been making efforts to promote ecological civilization and accelerate the construction of "wetland city". (Xinhua/Wu Gang)

Aerial photo taken on June 23, 2018 shows wetland of the Yellow River Delta national natural reserve in Dongying, east China's Shandong Province. The Yellow River, the second longest river in China, originates on the Qinghai-Tibet Plateau and empties into the Bohai Sea from Dongying City. The city has been making efforts to promote ecological civilization and accelerate the construction of "wetland city". (Xinhua/Wu Gang)

Aerial photo taken on June 22, 2018 shows the Qingfenghu Yellow River culture park in Dongying, east China's Shandong Province. The Yellow River, the second longest river in China, originates on the Qinghai-Tibet Plateau and empties into the Bohai Sea from Dongying City. The city has been making efforts to promote ecological civilization and accelerate the construction of "wetland city". (Xinhua/Guo Xulei)

Combo photo including undated file photos (top and middle) and photo taken on June 28, 2018 (bottom) shows the Shimen Forest Park of the Qilian Mountains national nature reserve before, during and after its environmental restoration in Wuwei, northwest China's Gansu Province. The Qilian Mountains, on the border of Gansu and Qinghai provinces, was designated a national nature reserve in 1988. However, many illegal mining projects and hydropower stations have sprung up as a result of lax supervision in recent years, inflicting significant damage to the environment. Provincial authorities have revised local environmental protection regulations to ban production activities, including mining, in the core and buffer zones of the Qilian Mountains nature reserve. Other measures include closing hydropower stations and relocating herders in efforts to protect the national nature reserve. (Xinhua/Fan Peishen)

Staff members check the environment monitoring system on the Qilian Mountains in Zhangye, northwest China's Gansu Province, June 5, 2018. The Qilian Mountains, on the border of Gansu and Qinghai provinces, was designated a national nature reserve in 1988. However, many illegal mining projects and hydropower stations have sprung up as a result of lax supervision in recent years, inflicting significant damage to the environment. Provincial authorities have revised local environmental protection regulations to ban production activities, including mining, in the core and buffer zones of the Qilian Mountains nature reserve. Other measures include closing hydropower stations and relocating herders in efforts to protect the national nature reserve. (Xinhua/Fan Peishen)

Aerial photo taken on June 20, 2018 shows the site of a closed mine in the Qilian Mountains national nature reserve in Jinchang, northwest China's Gansu Province. The Qilian Mountains, on the border of Gansu and Qinghai provinces, was designated a national nature reserve in 1988. However, many illegal mining projects and hydropower stations have sprung up as a result of lax supervision in recent years, inflicting significant damage to the environment. Provincial authorities have revised local environmental protection regulations to ban production activities, including mining, in the core and buffer zones of the Qilian Mountains nature reserve. Other measures include closing hydropower stations and relocating herders in efforts to protect the national nature reserve. (Xinhua/Fan Peishen)

This aerial photo taken on June 21, 2018 shows the Xi'an Expo Park located within the Chanba Ecological District in Xi'an, northwest China's Shaanxi Province. Aiming to serve as the "green lung" of Xi'an, the Chanba Ecological District has adopted an eco-friendly approach to its development. So far, six large ecological parks have been built here, covering 1,133 hectares of wetlands and 1,933 hectares of forests that are home to 206 bird species. (Xinhua/Shao Rui)

This aerial photo taken on June 21, 2018 shows a wetland within the Chanba Ecological District in Xi'an, northwest China's Shaanxi Province. Aiming to serve as the "green lung" of Xi'an, the Chanba Ecological District has adopted an eco-friendly approach to its development. So far, six large ecological parks have been built here, covering 1,133 hectares of wetlands and 1,933 hectares of forests that are home to 206 bird species. (Xinhua/Shao Rui)

This aerial photo taken on June 21, 2018 shows a wetland within the Chanba Ecological District in Xi'an, northwest China's Shaanxi Province. Aiming to serve as the "green lung" of Xi'an, the Chanba Ecological District has adopted an eco-friendly approach to its development. So far, six large ecological parks have been built here, covering 1,133 hectares of wetlands and 1,933 hectares of forests that are home to 206 bird species. (Xinhua/Shao Rui)